CA2188250A1

CA2188250A1 - Method and apparatus for recording sensor data

Info

Publication number: CA2188250A1
Application number: CA002188250A
Authority: CA
Inventors: Brian R. Hill
Original assignee: Individual
Current assignee: Prima Facie Inc
Priority date: 1994-04-19
Filing date: 1995-04-19
Publication date: 1995-10-26
Also published as: MX9604900A; EP0761051A1; US5497419A; US5646994A; EP0761051A4; WO1995028783A1

Abstract

A method and apparatus for recording sensor data. The analog and digital signals containing the sensor data are accompanied by a concurrent analog video signal. The analog signals are converted to digital form and highly redundant signals are compressed according to conventional compression technique. The resulting compressed and uncompressed signals are encrypted and stored on a removable hard disk.
The data stored on the removable hard disk can later be played back to reconstruct the original signals while assuring that the played back signals are correct reconstructions of the original signals.

Description

.
Wo 95/28783 Y~

r)PRcriDtion M13TElOD AND APPARAT~S 3~OR ___ __ _ SENSOR DATA

5TPrhn; rAl F; Pl rl The present invention relates to methods and ''L'l~ f or recording and, more part; clll Arly, to methods and apparatus for recording sensor data with video signals.

10 Backrround of thP InvPnt; nn Motor vehicles are an ;ntP~rAl part of modern Snr;Pt;Ps.

Beside providing the facility of I ''"'~L'~" Ling goods in the market place, they also LLa~ uL~ Tn;ll;nnR of people on a daily basis and are used to provide services, such as public safety services. The 15 burgeoning use of motor vehicles _as given rise to a complex and expensive l;Ah;l;ty system rnnrPrn;n~ vPh;r~ r ~ Latiorl. In nearly all states of the United States, for example, Al~t~ ' '1e ;ncllrAnre is required. Arcnrrl;nJly, much expensive l;t;rJ~t;nn ensues in rnnnPrt;nn with motor vehicle ~rr;-lPntc and other 20 ;nr;~PntR.

The massive system of pnl;r;Pc and claims that result ~rom the ;nQllrAnre c~veL~ye and related l;t;rJAt;nn are subject to fra~ lPn~

abuse. Current estimates ;n~3;r~A~te that thi8 r~ is on the rise, causing in~;L~as,ad cost to the system, eve~ in locales where 25 Arr;r1Pnt rates are ~7;m;n;Rh;nJ In addition to fraud, the rPRnl~lt;nn of claims relating to motor vehicles is an ;nPff;r;Pnt time-c _ n~ process that PYrPriPnrPR A~l;t;nnAl costs by relying heavily on a tort-based legal process. As one measure of the increased burden that this F' puts on society, legal costs 30 cnnrorn;nrJ automotive injury claims is increasing R;~n;ficAntly.

one problem related to these in-;Leased costs is the ~l;ff;rlllty in providing basic ~ facts cnnrPrn;n~ motor vehicle w095n87U 2I 8825 0 ;nr;~Pnt5 Beside the abuse of the process allowed by parti bringi~g suit in the hopes of an out-of-court settlement, costs are often cign;firAn~ly greater when a motor vehicle-related suit does end up in court. To combat these problems of ~c ~t;nn and S out-of-control costs, many ;ncllr;mrP PC a~d states in the United States are rnnc;~prin~ at;nn of ma~datory vehicle ;n~ect;nn~ and special invest;gAtinn p ~ Pl units. However, these approaches are expensive, too, and this expense adds to the overall costs of the transportation system.
One ArprnArh to helping curtail these costs is to provide better data rnnrPrn;n~ motor vehicle ;nr;~Pntc. This will help to curtail frAl~ Pnt claims. While other vehicle-borne systems have been ~Lu~osed to provide ;nfOrlT~,t;nn rnn~Prnin~ automotive ~rr;~lPntc, these systems are themgelves subject to frAll~lll Pnt 15 ~n;rll~t;nn. Ag one results, courts of law are not likely to give much ev;~lant;~l weight to such ;n~n~-t;nr~ systems unless they are secure .
Accordingly, it is ,1PC; rAhl e to have a vehicle-borne data collection system which . is capable of securely rPrnrtl;n~ data 20 rnnrPrn;n~ Arr;rlPntc Of course, such systems will have other Arlr~lir~t;nnc, such as other means of t~ OLLdtiOn and other s;tl~t;nnc ,~ - n~ secure ~Lt:se~Lvation of data cnnrPrn;n~ events, such as bank security systems.
25 S of tl'lP Tnvention According to one aspect, the invention is a method f or recording sensor data with a video signal to protect the sensor data. The se~sor data is cnnt~;nPd in signals from one or more sensors The method CPC the steps of a) encrypting the 30 signals from the one or more se~sors, b) - n;n~ the video signal and the encrypted signals to produce an output signal, and c) re~rdin~

W095/28783 21g82~
Ar~nrl;n~ to another agpect, the invention is a method for retrieving sensor data originally ~Ludu-ed by one or re sensors.
me sensor data is encrypted with a video signal to produce a recorded signal that protects the sensor data and being rnntA;np~
5 in signals from one or more sensors. The method _ ~Pc the steps of a) playing back the LecuLded signal to produce a played-back signal, b) decrypting the played-back signal to produce a video signal and one or more sensor signals rnntzl;nin~ data nris;n~l7y produced by one or more sensors, and c) pro 10 the one or more sensor signals to produce the sensor data.
~ rrnrf~; n~ to another aspect, the invention is a method f or recording sensor data with a video signal to protect the sensor data . The sensor data is rnntA; nP~l in signals ~rom one or more sensors. The method , ~P~ the steps of a) -, es~ing the 15 video signal to produce a cu~Lè~ ed video signal, b) n;n~
the ~ e~sed video signal and the signals from the one or re sensors to produce a digital signal, c) encrypting the digital signal to produce an output signal, and d) rPrnrti; ng the output signal on a recording medium.
~rrnrl;n~ to yet another aspect, the invention is a method for retrieving sensor data orig;nAlly produced by one or more sensors.
The sensor data is encrypted with a video signal to produce a recorded signal that protects the sensor data and being ~nntA;nPA
in signals from one or more sensors, at least one of the sensors producing an AnA~ og signal . The method comprises ehe steps of a) playing back the Lè~;uLded signals to produce a played-back signal, b) decrypting the played-back signal to produce a video signals and one or more sensor signals rrntA;n;n~ data nri,;"Al ly produced by one or more sensors, c) ~Pt~rm;";n~r whether any of the one or mor~
sensor signals are digital signals, and d) l~ u~ in~ the ~e or more sensor signals to produce the sensor data, inr~ in~

W0 9i5~i8783 ~ 2~ ~ r ~
converting the one or more~-i sens~r signals to produce a <;ULL~ J~"~fl;nj analog signal.
1~r ~rnrrl; n~ to a F'till ~urther aspect, the invention is a method for recording se~sor data with a video sighal to protect the sensor 5 data. The sensor data is rr~nt~;nf~A in signal8 from one or more sensors. me method comprises the steps of a) A~t~;n;n~ which of the signals from the one or more sensors are analog sensor signals and which of the signals from the one or ~Lore sensors are digital sensor signals, b) converting the data in the analog sensor 10 signals to one or more first digital signals, c) encrypting the digital sensor signals and the one or more first digital signals to produce second digital signalg, d) converting the gecond digital signals to first analog sig~als, and e) rPc~rt~;nr; the video signail and the first analog signals on a rf-rnrA;nrj medium.
~rrf~rfl;nr; to yet anotller aspect, the invention is an ~ R
for rerorA; nrJ sensor data with a video signal to protect the sensor data. The sen80r data is rrnt~;nf A in signals from one or more sensors . The -1~ . l , c , _ RPR an encryption circuit, a signal rr~r~ cR;nrJ circuit ard a recorder. me encryption circuit encrypts 20 the signals from the one or re sensors. me signal pror~Rr~;n~J
circuit : nc-R the video signal arld the encrypted signals to produce an output signal, and the Le iuLdeL records the output signal on a errr~;nrj medium.
According to yet another aspect, the i~lvention is an ~ r~ f 25 ~or rern-A;nrj sensor data with a videû signal to protect the sensor data. me sensor data is rrnt~;n~A in signals fr m one or more 8ellS0rS . me i~ r~tl~c ~_ _ RPr( a ~ _ r,n~ circuit, a signal processing circuit, ar~ encryption circuit and a I~;ULd~. me ~saion circuit compresses the video signal. The signal 30 Frr-PRR;nr~ circuit com~ines the c.",~L~sa~:~ video signal and the signals from the one or more sensors and produces a digital sign,~l th~L~:~LI . me encryption circuit encrypts the digital signal an _ _ _ _ _ _ _ . . .. ... . _ . _ . .

wOgs128783 2188250 produces an output signal th~L~fLU.... The ~c~ r records the output signal on a recording medium.
~~cnrA;n~ to an even further aspect, the invention is an ~ L'l~ C for recording 8ensor data with a video signal to protect 5 t~e se~sor data. me sensor data is rnnt~;nP(l in signals from one or more sensors. The ;Ipp~r~tllc ~P~ a dist;nrt;nn circuit, a first conversion circuit, an encryption circuit, a second conversion circuit, and a r~ùL.l~L. The dist;nrr;nn circuit ~lPtP~;nPs which of the signals from the one or more sensors are 10 a~alog sensor signals and which of the signals from the one or more sensors are digital sensor signals . The f irst conversion circuit converts the data in the analog sensor signals to one or more first digital signals. The encryption circuit encrypts the digital sensor signals and the one or more first digital signals to produce 15 second digital signals. The second conversion circuit convert the ~econd digital signals to first analog signals, and the ,~c,Ldel records the Yideo signal aIld the first analog signals on a recordi~g medium.
According to even still another aspect, the invention is an 2C A~tl~ for rernr~;ns sensor data with a video signal to protect the sensor data. The sensor data is cnnt~;nocl in signals from one or more sensors- The ~ c - . ~P~ means for encrypting, means for ~ n;n~ and means for rPrnrlin~ The means for encrypting encrypts the signals from the one or more sensors.
25 The means for - nin~ r nPCl the video 8ig~al and the ~;Lyu-ed sig~als to produce an output signal. The means ~or recr,r~l;
records the output signal on a rPrnr~7;n5 medium.
P-rr,~;n~ to another aspect, the invention is a method for retrieving sensor data originally ~LU-Iu~d by one or more sensors, 3 0 the sensor data being encrypted with a video signal to produce a ~-c~.lG~ signal that protects the sensor data and being cr,nt;l;n~d in signAl 8 from one or more sensors, at least one of the sensors wo95n8783 ~88~50 I~
rrn~ r; n~ an analog signal . me method , coc the steps of a) playing back the ~ e~ oC signals to produce a played-back signal, b) decrypting the played-back signal to produce a video signals and one or re sensor signals cr~nt~;n;nrj data rris;n~lly produced by 5 one or more sensors, c) ~lotorm;n;nr~ whether any of the one or more sensor signals are digital signals, and d) processing the one or more sensor æignals to produce the sensor data, inrl~.l;nJ
converting the one or more sensor signals to produce a r,.,, P81.l .. .1inr~ analog signal .
Drrr,rrl; nrJ to and even still further agpect, the invention is ain ~rr~rAt--R for recording sensor data with a video signal to protect the sensor data. The sensor data is ~Annt;~;no~ in signals from one or more sengor8. The Al~l.l Al ~IC ' COC means for compress, means for n;nJ, means for encrypting and means for 15 ror~r~;n~ me means for , ts--ing , esse~ the video signal to produce a _ ;r' video signal. The means for, n;nr combines the ~ _ ~sRed video signal and the signals from the one or more sensors to produce a digital signal . me means f or encrypting encrypts the digital signal to produce an output signal, 20 and the means for rPrr~r~l;nA; records the output signal o~ a recording medium.
In still yet another aspect, the invention is an ~l~ ; for recordir,g sensor data with a video signal to protect the sensor data. The sensor data is rrmtA;no~l in signals from one or more 25 sensors. me A~ C coc means for ~lot~rm;n;n~, first and second means for converting, means for encrypting, and means for recording. The means for ~ot~rm;n;nrj fi~trm;nC which of the signals from the one or more sensors are analog sensor signals and which of the signals from the one or more sensors are digital 30 sensor signals. The first means for converting converts the data in the analog sensor signals to one or more fir8t digital 8igral8.
The means f or encrypting encrypts the digital sen80r signals a~

~09~28783 2 1 8 8 2 5 0 PCrlUS9~ 8 the one or more first digital signals to produce second digital 8ig~als. The second means for converting converts the second digital signals to first analog signals, and the means for recording records the video signal and the first analog ~ignals on 5 a r.^~^nr~l;n~ medium.
Brief Description of th.^ Drawinrc Figure 1 is a srh^--t;~^ diagram of a first preferred '; of an ~~ , c of the invention.
Figure 2 is a s ~ ; c diagram of the structure of a data file, as stored by the ~L~LeLLed ^ ' ' q of the invention.
Figure 3 is a ~ ' -; c diagram of a second pref erred -~i of an^ppAr~t~lc of the invention.
Figure ~ is a f low chart of the program running within the 15 pref erred : ' c of the invention .
Figure 5 is a L 1"- q._,.l ~t;nn of a video image, illustrating a method for rnntrnll;ng and Ac8--r;nr~ the ;nterJr;ty of the image upon processing, storage and playback.
Figure 6 is a block . diagram of an ~l'l'^' ~l ,.c for playback of the data stored by the data Le~uLdèL of the present invention.
Figure 7 is a flow chart of the method of playing back the data stored by the data LeeuL-l_L of the present invention.
De~;lP-?Descr;~7t;-n of thP Tnv_nt;nn Figure 1 is a 8~' ~;C' diagram of a ~LeLeLLed ' '' ' of an Al.~.A,,.~..c of the invention. The sensor data ~,~C~J-~1, 10 can be adapted for rl^~ at or near the lnrAt;nn where the sensors are located. In the following ~iFltA;lF-~ description, it will be assumed that the data recorder 10 is located in an ::llltl ' ' 1 e (not shown) .
30 Within the Allt~ 1 e, the data Le.uLde- 10 can be placed in a rAcc~ . or, for greater security, can be pla ed in a more secure place such as a trunk. Of course, those skilled in th~

-w095n8783 2 1 8 8 2 S ~
~rt would provide approp~iate rrntn~tinn for the data Le~LdeL 10, ~or~n~l; nrJ upon the particular task to which the data ~ e~.uLdeL 10 is applied. For example, a data IecuLd~L 10 that is to be i~stalled in an ~ t~ e should probably be ch;~ from Arr~lr-r~tinnR due 5 to impacts, as well as t~ extremes and high humidity.
Other Arrl ;r~t;nnC will obviously have their own particular enviL~ ;tl factors to be rnnc;~rrrl irl the ingt~tllAt;nn.
In the rrl~f,~rr~, , the data LeCULdeL 10 ;nrlll~l~c a number o_ serLsors, such as ign;tinn switch 11, brake sensor 12, 10 ~r~ r~A~tnr sensor 14, steering colum.~n sensor 16, wheel rotation sensor 18, turn sig~al sensor 20 and ultrasound ~ t~rt;nn sensor 21. The data recorder 10 also irlcludes a source of video infnrr-t; nn such as a forward-facing charge-coupled device (CCD) miu~ . 22 and a recorder 24. The data Let uLdeL- 10 may also 15 include one or more optionally ;:l~r~;t;nnAl CCD m;r-- ~, such as CCD mi~LU~ Lo. 25 that can be pointed rearward.
The CCD m;~ J~ 22 ca~ be a co~ventional camera mounted on a universal mount. ~rrrnrr;~ttF- crF~r;f;rAt;nnc are that the CCD
mi~L- ~ 22 should be nrprAhlr in an opPrAt;"~ t ~ e range 20 from -10 Celgius to t60 Celsius and to a maximum relative humidity of 95'~. Further, the CCD mi.L- 22 should have A~-t~ ' ir shutter sensitivity ranging f rom 1/60 to 1/32000 seco~d and a r~cnlut;n" o_ at least 380 by 380 picture element (pixel) rows and columns. In .~t~-l;t;nn, the CcD m;l - 22 should have an 25 ;ll~m;"~tin" sen8itivity of 1 lux or le88.
In some l~mhr,~; R, it may be ~l~R;rAhl~ to place the CCD
mi-L. 22 on a pan/tilt m.~t in a, ~h-~rproof enclosure.
The CCD m.~i-L. 22 could ther~ be m~ted outside of a vehicle and ~qu;rp~ with r2dio, infrared or tlltr~cr,lln-l beacon-following 30 sensors. T ~11 t;nn of such sensors are well within the skills of those of the relevant electronic arts. Such beacon-following systems can be used to follow and provide video images of a person ~W0 95t28783 21 8 8 2 5 0 r carrying an appropriate beacon source. An important OEample is a mi~L~ adapted to follow public safety p~ ,Pl who are weaAng a beacon and whose motions and ~" ~ u ~ ; n~c can then be 211t~ tir~ ly recorded in video fornt. Further, if a radio or 5 infrared beacon i8 used, such a sy~tent could also provide an audio signal front the vicinity of the person wearing the beacon. The audio signal could carry the voice of the person wearing the beacon, and could be compressed, encrypted and Le~oLded with the data from the other sensors, as will be riPqrr;hP~l below.
me LecoLder 24 can be a convPnt;on~1 JVC time lapse cassette LeCUL~ièL, although other LeiUL~L~ could also be used.
me sensors 11, 12, 14, 16, 18, 20 and 21, and the CCD
mi~L~- 22 (and CCD mi~L~ 25, if ;nr1t~lP-1) are to the recuLdeL 24.
lS me various sensors 11, 12, 14, 16, 18, 20 and 21 may include a local tr~nc~llrPr at the lorAtinn of the variable being sensed and a remote tr~nC~ r Pr placed more closely to thê Lèco, der 24 than the lorat;nn of the variable being sensed. For exan~le, the wheel rotation sensor 18 may include a local tr~ncrlllrPr that transfornts 20 some of the rotAt; nn~l energy i~tto electrical energy and a remote I .,."c.~ . that converts the PlPrtr;r~l energy into an ele~:LL, _ ~.; c signal that can be Le~:UL-l~d by the I e!l 1.. .l~\ 24 .
me local tr~nC~ rPr of the wheel rotatio~t sensor 18 may be a e~l f errous -based cog wheel that rotates with the wheel and 25 the remote tr~n~ Pr can be a ro1llrt~nre-sensing tr~nc~lllr~r ~tat transfornts the ~lPtPrtP~ pulses in the ~nPti ~ field ~o an P1ertr;~A1 signal that is ~Lu~,essed for optimal use by the data L~_uL~er 10.
.C;m;l;lrly, the 1ll~ PtPrt;~n sensor 21 can have 30 forward- or side-located ~, c that produce signals that are further pLu~essed at a remote lr,r~ti nn . In one L ~, the ultrasound rlPteoti~n sensor 21 can include a p11lr~ y of wo95n87u ~188Z5~ P~1/1 ..l tr~cnn~ r tr~nRflllrPrR mounted at the ~ront and around the sides of the vehicle. From those lor~tinn~, tr~nRflllrPrS produce and/or receive llltr~cnn;r sir~nals to flPtorminP the; ';~tP buLLuu~ings of the vehicle and produce signals that carI be l" ~ sf fl to produce 5 an alarm signal that will activate the inventive data recorder 10 to record the rrQY;m;ty of other nearby vehicles. ~PrPnfl;n~ upon the particular signal rrorpRR; ng used, in one : ~ ' such an Illtr~olln~l fletPct;r~n sensor 21 can be used to monitor the driving habits or the vehicle's operator~s).
T~e recorder 24 shown in ~igure 1 is a hardware-based 1 PmPnt;~t; nn of an PTnhrfli of the invention. The LecuLdt:L 24 includes a mass storage device 30, a bus 32, a signal processing circuit 34, a signal conversion circuit 36 and a sensor input/output (I/O) circuit 50. The mass storage device 30, the signal prorPRR;n~ circuit 34, and the signal cor,version circuit 36, and the sensors I/O circuit 50 are all rr~nnp~tp~l to the bus 32.
The mass storage device 30 can take several formæ. In one preperred PmhO~7i the masæ storage device 30 is a ~-gnPt; r tape recorder (sper;fiP~l above) that records on a ---~nPt;r tape ;nrlll~lP~7 in a removable r;~Rcpttp~ In other ~ R, the maSS storage device 30 can be a solid-state fla8h memory card or other removable memory mediums that store data. E~amples are 2.5 and 3.5 inch removable disk drives capable of storing at least 120 megabytes of data .
The signal prorPcc~;n~ circuit 34 i~cludes a cer~tral processing unit (CPIJ) 40, a random access m.ery (RAM) 42 and a clock 44 that are r-nnnpctpfl tsrJPthpr i~ conventional fashior. These cnnnPrtPd ' R allow the CPU 40 to process se~80r and other signal8 received from the bus 32 in ar~ 7~-~ ~rP with clock signals produced by the clock 44 and to record the results of the signal processin nrPr~t;nnc in the RAM 42. The actual signal prsrPRR;nr; ~__E_ by the CPU 40 is fl~ upo~ a program which is i~stalled in the ,=

~ 0 95128783 ~ t 8 8 2 5 ~
CPU 40 when the data recorder lO is first turned on. Such ~JL~_ n~ is ConvPnt;nnA1 to those skilled in the art of computer LLU` 'n~, ~WO aspects of the nPrPSsAry UL~_ 'n~ are worthy of sper;f;c note, however. The first is that the CPU 40 is pLU' ' to convert digital aiynals from one format to another.
me second is that the CPU 40 is also UL-_ ' to encrypt the ; nCnr~-t j nn in the signals . The actual encryption method can be any one of many available pn~c;h;l;t;P~: me preferred form, however, is a public key encryption method chosen from the many known public key encryption methods.
The signal conversion circuit 36 is used to convert the video signal from the CCD miuLu~ (s) 22 (and 25). At a minimum, the siynal conversion circuit 36 must convert the analog video signal to digital data. ~urther, the signal conversion circuit 36 can control the SP~lPnr;n~ of the video signals if there is more than one mi~:L. . The siynal conversion circuit 36 can include a multiplexer that controls which CCD mi~L. is being recorded at a yiven time . As will be ~lD~rr; hPd below, the rate at which the video siynals are 8-r 1 trhP~ can be made a function of the state of alArm of the recorder lO. Drcnr~;n~ly, the signal conversion circuit 36 can be made to respond to alarm signals produced by the siynal yL.,. ~ circuit 34. ~1tPr" it;vely, the siynal conversion circuit 36 can take video gignals from all of the CCD m; rra in apPrA~;nn and produce a CU11~ULL~ UL1Y ~ - tP video siynal, such as a split screen video signal. The siynal conversion circui~
36 can also receive date and time siynals from the signal prorPcs;n~ circuit 34 and produce video L~yL~ At;nn~ of those date and time signal8 in the analog video 8ignql before dig; t; 7;ns the video signal.
In A~l~;t;on, the siynal conversion circuit 36 1 _ .3~es the highly LP ~ l video signals from the CCD miuL. 22 and produces therefrom a compressed digital siynal that it trA"~Pr~ to .

w0 9~83 2 1 8 8 2 ~
the bus 32. The , ~ srion op~rPt;nn is performed by hA - c: in the signal conversion circuit 36. This hardware convPnt;nn~lly takes the form of an 7rrli~rpt;nn-srer;fic ;nte~rAto~l circuit (ASIC) that performD JPEG ~ A~;nn. ~ltPrnpt;vely, and in some 5 Arrl;r~tinnc, it may be prPfPr:-hlP to perform - _ ~:D~ion of the video daSa through other hardware means, such as an ASI~ that performs MPEG or other we~ own ~ , _sDion terhni~loc ~per;f;~lly, the compression portion of the conversion circuit 36 CU..~L~:DSe5 data received from the CCD mi~;L, c. 22, as well as 10 any of the optional ~ ; t; nnAl CCD mi.:L-~ - 25 that may be in use in the SrPr; f; ~r ~ LL~ omh~rl; that is 8lli tAhl P for a particular ;~rFl; Cpt; nn, In npPrAt;nn, the ~ecu~dc:L 24 receives signals from the sensors 11, 12, 14, 16, 18, 20 and 21, through the sensor I/O
15 circuit 50 and the bus 32. The rPcnr~Pr 24 also receives signals Erom the CCD miul. 22 (and any pncc;hlP ~t;nn~ rlrl;t;nn:~l m; r--_ ~ 25) through the signal co~version circuit 36 . The signal prorPc~;n~ circuit 34 receives the sensor and digital video signals through the bus 32, rroraccPC the signals, and sends the 20 resulting pLucessed digital signals to the mass storage 30 for recording .
Since the data rPrnr lo~l in the mass storage is encrypted, its 8ecurity during playback can be given a very high degree of ~ D"'..'.''t'. If a party wished to alter the data L',~ in the 25 mass storage, the encryption system applied would have to be ~iPfP~tpfl and the rer~r~Pd data Ler~ d over with counterfeit data that make rnntPYtl~l sense. In general, it would be very ~:I;ff;r~-lt to do so. It would be; hl~, even given the massive amount of ; n~ power available today, to rmlntPrfP; t the data that c n 30 be stored by the present inve~tion if a time constaint is applied, even a time co~straint ~ ~d in years.

~0 9~83 218 8 2 ~ 0 ~ s n l ~
In some ~prl;r;lt;nnc, it may be APc;r~hlf~ to omit the sigrlal conversion circuit 36 and transfer the data from the CCD
mieL. 22 directly to the bus 32. In other :I~)l;r~t;nnc~ it may be APCi ~ hl P to omit the encryption of the digital data 5 received by the signal proc~cc;n~ circuit 34.
As applied to one particular desired spPrif;c; '; of the invention, the signals from the CCD mi.:-. 22 can be , essed by the c~u~Le,~ion circuit (such as a JPEG circuit) .
Then the ~ , ~e~sed data, along with the sensor data can be mixed 10 with clock data before encryption, 80 that the encrypted data includes cnnt c recnrA;n~g of the date and time (clock sig~al), the sensor pr~c;t;nnc (sensor data) and the visual scene (video data). If desired, the date and time ;nfnrr-t;nn can be inserted into the visual scene (through convPnt; nn~l circuitry a~d 15 prorpRc; n~, not shown) .
Figure 2 is a 8~ ; r diagram of the structure of a data file, as stored by the preferred ~ ~ of the invention. me data file 60 ig repregented as a Le,~ r area rnnt~;n;n~
digital data which are stored in a memory such as the RAM 42 of the 20 signal prorPcs;n~ circuit 34 in Figure 1. However, the data have a format which i8 useful when reading and playing back the data.
.Sper;f;r~lly, the data file rnnt:i;nc header data 62, video data 64 and se~sor data 66, in that order. The header data 62 ;nrlllAPc an ;nA;r:~t;nn of the file format that is used in the storage of the 25 data in the file, the version of the recorder on which the data were LeeuLded, a cu8tomer IAPnt;firAt;nn number, and aAA;t;nn~l portions LeseL ved for future use . The video data 64 is 8-bit gray scale data, Le~ ;n~ 256 different levels of gray.
A1tPrn;~t;vely, the video data 64 can Le~LesellL a color video image.
30 The video data 64 can be pn~Ll ~,rP~ , after th-e analog video signals have been A;~;t;7PA, by the insertion of a special digital data portion 68 that rnnt~l;nc dc ~ y data. Most often the , J ~
wo gs~ 2 ~ ~ 8 ~ 5 0 ~L y data will be the date and time at which the images in the video data were imaged by the mi~:L. _ (5) 22 and 25 .
However, the lL y data could be ~ to include rl;g;t;7Pd L~Lyc~ ;nnc of the outputs of some or all of the 5 sensors 11, 12, 14, 16, 18, 20 and 21.
While this ~LU''6dUL~: may '~ the video data 64, it can be use~ul to provide a first level of security to the video data by reserving 8r~r; f; ~ pixels L 1~ _q~ by the video data 64 which are used by the fonts of the rh~ractprR used to Lt:~L~ e~L the 10 do, y data in the digital data portion 68. The font is chosen so that it is Yery ~; ff;rlll t to L~Ludu~e if; n attempt is made to modify the video data 64, but ig very easy to verify as valid if no attempt to modify the video data 64 has been made.
The sensor data 66 ;nrlllrl~c digital L~L~ t;nnR o~ the lS value of the variable(s) for each of the sensors ll, 12, 14, 16, 18, 20 and 21. Typically, it is d~Rir~h1e to encode the digital sensor data 66 to ~1; Rronra;e ; _ nrJ . However, the primary security for the sensor and other data in the file format is provided by encry-ption that is applied after the data in the file 20 are ~ Pfl-There are further ~ILU~ dUL S to hF-; ghtPn the security of the data, part; r~ r1y the video data 64 stored in the ~ile format 60 ûne approach is to encode the gray scale (or color) ;nfr,rr-t;nn in the file format 60 80 that cnnq~r~t;ve digital values do not 25 L~:~L~ L rnnc~cllt;ve grays or colors. In this way, the data are Le:yL~8~L~ed i~ a false gray (or color~ fashion that will rl;~rr,l~rase n~.
Figure 3 is a _ -; r diagram of a second prf~f~rred ' m~nt of an ~L~ ,c of the invention. The LeCuL~ L 24 shown 30 in Figure 3 is a software-based; ,~ ~t;nn of an ~
the invention In this _ - c diagram, ~ _ q which serve . ` 2i8825~
~095128783 1_"~ I
the same purpose as those described in Figure l are given the same reference l R as their counterparts in Figure 1, In Figure l, irjn;t;rn switch sensor ll may take the form of a ' conventional ignition switch that can be ~rr~CR~ 80 that it is 5 pn~5; hl e to rlrt~rm; nP whether the ignition switch is turned on, Turning on the i,~nit;nn is g~n~r~lly a good signal that the vehicle is about to be r,p~r~te-l and may, in some system, signify that the data recording process should begin.. In arlrl;t;r,n, the brake sensor 12 may take the form of a brake ~JLel3tiUL~ sensor, the 10 Arrl~lorAtr~r sensor 14 may take the form of a throttle pr,c;t;~n sensor, and the steering column sensor 16 may take the form of a wheel prc, it; nn sensor.
The sensors can also include a speed input sensor 23 ; nr~ ; nrJ
a toothed wheel that rotates as the vehicle moves and produces 15 pulsed signals in ~rrnr~l~nre with the rQt~t;nn~l speed of the wheel. Another r~t;nn~l sensor is a Global pr,~jt;nn;n~ Satellite receiver 52 w~ich receives prJ~citirJnAl signals through its roof-mounted antenna 54 and ~Lu~luces sensor signals that are used by the sensor data L~-_ULde:L 10 to ;n~;r~te the glohal lor~t;nn Of the 20 vehicle in which it is installed lwithin 30 meters). A further optional sensor is a door open sensor 56. me door open sensor 56 can be useful in identifying C-;t~l~t;rnc in which it is ~;rihle to start rernr~l;n~ data, even if the vehicle is not started. It can also be useful in identifying sitl-~t; r,nc in which a public safety 25 officer has left the vehicle, signifying that a beacon-following system rrntrr,ll;n~ the pn;nt;n~ direction of the CCD mi..~ - a(S) 22 and 25 should be activated.
The mass storage device 30 of the ecu..leI 24 can be a removable hard disk having 500 megabytes of storage capacity. The 30 recording time for the mass storage device is ~l~rF-ntll~nt upon the ;n~ rate of the signals which are to be stored.

W0 95/28783 2 1 8 8 2 ~
The signal conversion circuit 36 is ~-nnn.ot-tf~A to one or both of the CCD mi ~ - c 22 and 25 and includes flash converter circuitry to ~uickly tr~ncfnrm the analog video signals ~rom the microcameras to digital form. In thig form, and in ~onr~linAtinn 5 with the signals rroflll~ecl by a system timing circuit, a _rame buffer circuit prsA~ framed A;~;t;7Pfl video data that are tr;~ncfPrrefl to the bug 32 for LL~ ULL to other 1- e c of the data L~:~.U~ d~::L 10, such as the signal processing circuit 34.
The signal pro,-Pcs;n~ circuit 34 includes a CPU, such as an Intel 80386 mil Lu~-u~ssoL, which is cnnn~-tecl to a dynam.~ic RAM and to a real-time clock in ~c~ with the good Pn~;nPPr;
practices well-known to those skilled in the Pl Prtrnn; .~c hardware arts. The data produced by the miuLuyLuces~ùr are tr7n~;ttpfl to the bus 32, which tr:~ncfP~c them to the appropriate h;3rfl~o-rP
- of the sensor data Le!rl~ - 10, such as the mass storage device 30. In specific ~rrl;c~t;nn, the miuL~L~u - Y~ of the signal processing circuit 34 receives the data cnnt~;n;n~ header, video and sensor data ~r~nrfl;n~ to the file format 60 (see Figure

2). As the data are received, the microprocessor applies a compression algorithm, such as the LWZ algorithm, to the received data and stores the data in compressed form in the dynamic RAM.
The micrnrronP~nr then applies an encryption al ~nr; tl to the stored data and tran~fers the resulting encrypted and ~ e!s~ed data to the mass storage device 30 through the bus 32. In the mas~
storage device 30, the data are stored in a hard disk that i~
removable from the mass storage device 30. The removable hard disk ~nnti~;n;n~ the encrypted ( _ esged data can be stored in a convenient l~n~t;nn for later retrieval and replay of the data.
me power supply 70 of the data L~uuLd~l 10 shown in Figure 3 i8 an integral part of the data recorder. The power supply 70 is normally rnnnpct~fl to the vehicle' 8 battery. However, to prote~t 95128783 2 ~ 8 8 2 S
~
the data Le- ~LdaI 10 from llnP~e~tPrl disruption and/or ;ntPnrlPd sabotage to the cnnnPr~;nn between the power supply 70 and the battery, the power supply 70 ; nrl tl~PC a backup battery 72 . The backup battery 70 will supply power to the data LeccLdcr lO in the 5 event that the cnnnPct; nn between the power supply 70 and the vehicle's battery is broken. In ;~ ;t;nn, the power supply 70 can be used to extend the time that the data Lc~oLdeL 10 can record data for a period of time after the Alltl ' 1P'8 i~nit;nn switch has been turned of f .
Fi~3ure 4 is a flow chart of the program running within the preferred c ' of the invention shown in Figure l. The program is simultaneously A~ , l; Ch; n~ two tasks . One task is to receive and process data from the sensors. The other task is to receive and process data from the video camera ~s) 22 (25) and to 15 combine the video data with the sensor data. The nP~l data is then _ e:s~ed, encrypted and stored to disk for later retrieval and replay in a, cuL~-ce with methods known in the prior art. The replay methods -, cP the iIlverse gteps to those ~Pcrr;hP~9 below in carrying out the Pnro~; n~, encryption, ~ sion a~d recording 20 steps.
In ~rrnr~lAnre with sigIlals pL'J'l' ~ 3 by the system clock (block 100), the video data task starts (block 102) and ~ ti'~PC a frame of video data ~ 7 by one or both of the mi. L. ~ ~block 104). The system clock signals control when the rPA~lin~c from the 25 sensors and the video camera(s) are taken. Typically, the sensor signals are sampled four times per second and the ~ideo camera data are sampled once per minute. ~Iowever, the data can be sampled at ~1i ffPrPnt controllable rates as r3Pcrr;hP~9 below. The digitized video data is ~ rP ,-cd to the dynamic RAM (block 106) and 30 intf~ L~ ,P~l with time/date signals produced by the 8ystem clock, the time/date signals rhArArtpr; 7; nrJ the time and date at which the signals are pro-l-lrPrl (block 108). The sensor data are a3~so Wo 95/28783 2~ ~ 8 ~ 2 5 O r~
appended to the stored video and time/date signal data (block 110) in the file format described above, ~:~sed ~block 112), encrypted (block 114), and stored to disk (block 116) for later retrieval and replay. men this task of the computer program 5 awaits a further signal from the system clock, at which time it will begin again at block 102.
In the other task, the program reads the sensors when the appropriate signal is produced by the system clock (block 118 ) .
The sensor readings are taken frequently, allowing them to be 10 ~L`LI~t5~d rlis;t~lly and/or statistically before they are made available as sensor data by the step L~ c.~ 1 by block 118.
miS program task then ~ _ as the sensor data to trip points or thresholds (block 120) and ~lPtP~;nf~C whether an alarm should be produced (block 122). In the alarm rnn~;t;nn, when the CCD
15 mi~:LL c are normally inactive, they are activated to record the events that caused, and the sensor data that resulted from the alarm condition. E~owever, if the CCD video mi.;L. ~ are normally active, their signals may be sampled more frP~lPntly in the case of an alarm to ;nrr~7ce the chance that the event 20 prompting the alarm cnn~;t;nn will be ~ _lPtPly recorded.
~xamples of such trip points are a particular vehicle speed or a p~rt;r--l~r amount of steering wheel motion. In the first example, the step of block 12 0 can detect when the vehicle speed exceeds the trip point, and the step of block 122 can ~PtP~;nP that an alarm 25 should be ~ fl In the second example, the data recorder analyzes the ~ n; t~ and r~ "' y of the steering motions to ~ct:-hl; ~::h when the trip point has been PYrpp~
If an alarm is to be ~LULIU~ed, the alarm signal is ~Lu.essed (block 124), causing aljuffi in the _l ;n~ rate, an alarm 30 timeout and reset cnn~l;t;nn are est7hl;chPd (block 126) and the program returns to block 118 to read the sensors again. To save storage space in the mass storage device 30, the alarm timeout is ~1~ 95,~,83 2 ~ 8 8 2 ~ ~ r~l est~h-; ch~A to allow the system to collect possibly relevant da~a without requiring an lmA~; r~hl y large amount o~ the renorA;
medium. me tlllr~t;~n of the alarm timeout is a function of che reason for the alarm. For example, if the alarm is caused by the 5 vehicle ~ s speed f~ Ai n~ a desired threshold, the data Le~uLdeL ~0 should be activated only as long as the speed is above the desired threshold. On the other hand, if the alarm is caused by errati~
steering ~u~, R, the alarm cnnA;t;nn should last beyond the tim~s when the erratic steering, ~ cease.
If the alarm is not to be yLuduced, the sensor data are stored in an array in memory (block 128) for use by the append sensor data step (Le~Lt:SeLlLed by block llO) of the other task of the program, and the present task of the program returns to block 118 to read the sensors again.
Figure 5 is a L~L~c~ ;nn of a video image, illustrating a method ~or controlling and ~ r; n~ the ; n~e~r; ~y of the image upon proc~;n~, storage and playback. In ~rFl ;r~;nn~ wher~
, ~s:.ion o~ the entire video image would be i hlo and ye~
the integrity o~ the video image 80 must be ~LeseLved Isuch as in a 20 real-time recording and playback system), it is pnss;hle to sample and e s~ only a portion of the video signal ~rom the CCD
mi-L. 22 and then to combine this signal with the sig~als from the various sensors 11, 12, 14, 16, 18, 20 and 21 before encrypting the resulting data. me video image 80 can include an 25 image area 82 and ~n~r~lly an area 84 in which the date, time an~l status of various sensors (S1, S2 and S3) are displayed. In ~AA;~;nn, both the entire video image 80 and a subportion 86 o~ ~he video image 80 are - essed.
me entire video image 80 need not be encrypted before 30 storage, since the subportion 86 o~ the video image 80 is e~crypted and preserved ~or decryption and comparison to the stored image 70 to assure that the stored image is valid. Instead the entir~ ~ide~

W095~28783 ~ ~8 2 ~
image 80 is convertea to the file format but not rrmhinP~l with any sensor data . Rather, the subportion 86 is ~ _ essed and ' n~d with the sensor data and then encrypted. P Prs giving the lor~t;nn of the subportion 86 are incorporated into the header data 80 that it will be pnqc;hl e to correctly compare the decrypted and ~ssed subportion 80 with the appropriate part of the decompressed entire video image 80. The subportion 86 can be placed at any desired lor~t;nn in the entire video image 80.
However, if desired, the lor~t; nn of the subportion can be changed 10 randomly (say, to a subportion 86' ) so that a potential rm~ntPrf~; tPr would be unable to know which subportion &6, i_ any, of the entire image ao was used to validate the played-back _ e"sed entire video image 80.
Figure 6 is a block diagram of an ~rr~r~tllc for playback of 15 the data stored by the data LeeuLlèL of the present invention. ~he playback lrr lr~tl-c 140 includes a playback unit 142, a decryptio~
circuit 144, a ~;P~ es,.ion circuit 146, a playback signal processing circuit 148, a video display unit (VD~) 150, a speaker 152 and a sensor display ;L54. me playback unit 142 includes a 20 control panel 155 from which a user of the playback ~rp~r~tl~C 140 can control the playback process, ; nrl ~ ; n~ entry of any data needed to f~r;l;t~te the decryption process, such as entry of the second ~l-nr-hl; chPtl) ' of any public key encryption system that may be in use. The playback unit 142 accepts the removable 25 hard disk t_at was removed from the mass storage device 30, and plays back the removable hard disk to reproduce the digital data stored on the removable hard disk. me signals Le~Le~e~lLing the digital data are transmitted to the decryption circuit 144 which removes the ef~ect o_ the encryption performed on the data prior tû
30 storage on the revable hard disk drive. me decryption circuit 144 pr~lllr-~c a _ e~Se~ signal and an, _ ' signal, ;nrlll~ nr;r~;n;ll gensor signals. The _ e~ d signal is ~9sn8783 21882~0 l~l,.
received by the ~1P _ es~ion circuit 146 which produces a ~e _ ~ ~ video signal and a ~ ' g _ ès3ed sênsor sir;nal . me _ essêd signal from the decryption circuit 144 and b~th of the tlPI ~ signals from the de _ enbiOn circuit 146 æe 5 received by the signal ~Lu~l-cb;n~ circuit 148. In response, the signal prorPRc; "g circuit 148 produces an analog video signal and an audio signal. me analog video signal is received by the VDIJ
150 which causes the VDU 150 to reproduce the nriginAl images.
Also, the speaker 152 receives the audio signal and reproduces the 10 origin_l audio signals that Arr~rAn;P~l the n~;g;nAl images. In Ar~;t;nn, the sensor display 154 receives the sensor signals and reproduces their original readings.
Figure 7 is a f low chart of the method of playing back the data stored by the data Le~oLdeL o~ the present invention. In this 15 method, the digital signals recorded on the removable hæd disk are played back (block 160). Next, the encrypted digital signals among the played-back signals are decrypted (block 162). Any , ebbed signals ; nrl ll~lPcl among those that were originally played back or later decrypted are then decu-~Lebs~d (block 164) and the resulting 20 uncompressed and ~1P~ _ essed signals are ~Luu~:bbed to produce audio signals, video signals and sensor signals that were originally concurrent (block 166). me audio sigQals are then played, and thê ~ video and sensor signals are displayêd (block 168), thereby reproducing the original video, audio and 25 sensor signals. In the case where only a portion of the original video image is encrypted, the signal prorPcc; n5 circuit 148 also compares the ~ essed decrypted subportion 86 o~ the entire video image 82 with the proper portion o~ the ~1P~ _ essed e~tire video image 82 before displaying the tlP~ _ ess~d êntire video 30 image 82. I~ there are discrPrAnr;~cl the signal prors~C;n~-circuit 148 will alert the user to the type and ~or~t;nn o~ the discrPrAnr; PC, w0~83 ~88~5~
The ~L~r~:LL~:d . ~' of the present inve~tion has been in detail suf~icient ~or one skilled in the electronics and ra~io ~Lt:~U~,y arts to understand the invention. Such skilled 5 persons, however, could devise alternative ~ to that ;hP~l herein while L. ;n;n~ within the scope o~ the :~rp~n~
claims. ~rcor~;n~ly, the scope o~ the inventio~ is to be limited only by the ~L~ claims.

Claims

1. A method for recording sensor data with a video signal to protect the sensor data, the sensor data being contained in signals from one or more sensors, the method comprising the steps of:
a) encrypting the signals from the one or more sensors;
b) combining the video signal and the encrypted signals to produce an output signal; and c) recording the output signal on a recording medium.

2. The method of claim 1, wherein step a) comprises:
a1) transforming the signals from the one or more sensors to digital signals; and a2) encrypting the digital signals in accordance with a digital encryption procedure.

3 . The method of claim 2, wherein step a2) includes encrypting the digital signals in accordance with a public key encryption procedure.

4. The method of claim 2, wherein step a1) includes digitizing analog signals produced by some of the sensors and combining the digitized analog signals with digital signals produced by the remaining sensors.

5. The method of claim 1, wherein step b) includes mixing the video signal and the encrypted signal.

6. The method of claim 1, wherein step b) includes modulating a carrier signal with the video signal and with the encrypted signal.

7. The method of claim 1, wherein the video signal and the signals containing the sensor data are digital signals, step a) includes encrypting the digital signals in accordance with a digital encryption procedure and step b) includes digitally combining the video signal and the encrypted signals.

8. The method of claim 1, wherein step a) includes encrypting a signal from a clock.

9. A method for retrieving sensor data originally produced by one or more sensors, the sensor data being encrypted with a video signal to produce a recording signal that protects the sensor data and being contained in signals from one or more sensors, the method comprising the steps of:
a) playing back the recorded signal to produce a played-back signal;
b) decrypting the played-back signal to produce a video signal and one or more sensor signals containing data originally produced by one or more sensors; and c) processing the one or more sensor signals to produce the sensor data.

10. me method of claim 9, wherein at least one of the sensor signals is a digital signal that has been encrypted with a digital encryption procedure.

11. me method of claim 10, wherein the digital encryption procedure is a public key encryption procedure.

12. The method of claim 9, wherein the sensor signals and the video signal are mixed.

13. me method of claim 12, wherein the video signal is modulated with a carrier signal and with an encrypted sensor signals.

14. A method for recording sensor data with a video signal to protect the sensor data, the sensor data being contained in signals from one or more sensors, the method comprising the steps of:
a) compressing the video signal to produce a compressed video signal;
b) combining the compressed video signal and the signals from the one or more sensors to produce a digital signal;
c) encrypting the digital signal to produce an output signal; and d) recording the output signal on a recording medium.

15. me method of claim 14, wherein step a) comprises:
a1) digitizing the video signal to produce digital signals; and a2) compressing the digital signals in accordance with a digital compression procedure.

16. The method of claim 14, wherein step c) comprises:
c1) encrypting the digital signals in accordance with a digital encryption procedure.

17. The method of claim 16, wherein step c1) includes encrypting the digital signals in accordance with a public key encryption procedure.

18. The method of claim 14, wherein the video signal and the signals containing the sensor data are digital signals, step a) includes compressing the digital signals in accordance with a digital compression procedure, step b) includes digitally combining the video signal and the encrypted signals, and step c) includes encrypting the digital signal in accordance with a digital encryption procedure.

19 . A method for retrieving sensor data originally produced by one or more sensors, the sensor data being encrypted with a video signal to produce a recorded signal that protects the sensor data and being contained in signals from one or more sensors, the method comprising the steps of:
a) playing back the recorded signal to produce a played-back signal;
b) decrypting the played-back signal to produce a video signals and one or more sensor signals containing data originally produced by one or more sensors;
c) determining whether any of the one or more sensor signals are digital signals; and d) processing the one or more sensor signals to produce the sensor data.

20. The method of claim 19, wherein at least one of the sensor signals is a digital signal that has been encrypted with a digital encryption procedure.

21. The method of claim 20, wherein the digital encryption procedure is a public key encryption procedure.

22. The method of claim 21, wherein step d) includes decompressing any digital sensor signals.

23. The method of claim 22, wherein the video signal is modulate with a carrier signal and with an encrypted sensor signal.

24. A method for recording sensor data with a video signal to protect the sensor data, the sensor data being contained in signals from one or more sensors, the method comprising the steps of:
a) determining which of the signals from the one or more sensors are analog sensor signals and which of the signals from the one or more sensors are digital sensor signals;
b) converting the data in the analog sensor signals to one or more first digital signals;
c) encrypting the digital sensor signals and the one or more first digital signals to produce second digital signals;
d) converting the second digital signals to first analog signals; and e) recording the video signal and the first analog signals on a recording medium.

25. The method of claim 24, wherein step c) comprising:
c1) encrypting the digital sensor signals in accordance with a digital encryption procedure.

26. The method of claim 25, wherein step c1) includes encrypting the digital signals in accordance with a public key encryption procedure.

27. The method of claim 25, wherein step d) comprises:
d1) compressing the second digital signals in accordance with a digital compression procedure.

28. The method of claim 25, wherein step e) includes mixing the video signal and the first analog signal.

29. The method of claim 25, wherein step e) includes modulating a carrier signal with the video signal and with the first analog signal.

30. A method for retrieving sensor data originally produced by one or more sensors, the sensor data being encrypted with a video signal to produce a recorded signal that protects the sensor data and being contained in signals from one or more sensors, at least one of the sensors producing an analog signal, the method comprising the steps of:
a) playing back the recorded signals to produce a played-back signal;
b) decrypting the played-back signal to produce a video signals and one or more sensor signals containing data originally produced by one or more sensors;
c) determining whether any of the one or more sensor signals are digital signals; and d) processing the one or more sensor signals to produce the sensor data, including converting the one or more sensor signals to produce a corresponding analog signal.

31. The method of claim 30, wherein at least one of the sensor signals is a digital signal that has been encrypted with a digital encryption procedure, and step d) including decrypting the digital signal according to the digital encryption procedure.

32. The method of claim 31, wherein the digital encryption procedure is a public key encryption procedure.

33. The method of claim 32, wherein step d) includes decompressing any digital sensor signals.

34. The method of claim 33, wherein the video signal is modulated with a carrier signal and with an encrypted sensor signal.

35. Apparatus for recording sensor data with a video signal, the sensor data being contained in signals from one or more sensors, the apparatus comprising:
an encryption circuit to encrypt the signals from the one or more sensors;
a signal processing circuit to combine the video signal and the encrypted signals to produce an output signal; and a recorder to record the output signal on a recording medium.

36. The apparatus of claim 35, wherein the encryption circuit includes:
a digitizing circuit to transform the signals from the one or more sensors to digital signals; and a digital encryption circuit to encrypt the digital signals in accordance with a digital encryption procedure.

37. The apparatus of claim 36, wherein the, digital encryption circuit includes a circuit to encrypt the digital signals in accordance with a public key encryption procedure.

38. The apparatus of claim 36, wherein the digitizing circuit includes:
an analog-to-digital circuit to digitize analog signals produced by some of the sensors; and a combining circuit to combine the digitized analog signals with digital signals procedure by the remaining sensors.

39. The apparatus of claim 35, wherein the signal processing circuit includes a circuit to mix the video signal and the encrypted signal.

40. The apparatus of claim 35, wherein the signal processing circuit includes a modulator to modulate a carrier signal with the video signal and with the encrypted signal.

41. The apparatus of claim 35, wherein the video signal and the signals containing the sensor data are digital signals, the encryption circuit encrypts the digital signals in accordance with a digital encryption procedure and the signal processing circuit digitally combines the video signal and the encrypted signals.

42. Apparatus for retrieving sensor data originally produced by one or more sensors, the sensor data being encrypted with a video signal to produce a recorded signal that protects the sensor data and being contained in signals from one or more sensors, the method comprising the steps of:
a play-back circuit to play back the recorded signal to produce a played-back signal;

a decryption circuit to decrypt the played-back signal to produce a video signal and one or more sensor signals containing data originally produced by one or more sensors; and a signal processing circuit to process the one or more sensor signals to produce the sensor data.

43. The apparatus of claim 42, wherein at least one of the sensor signals is a digital signal that has been encrypted with a digital encryption procedure.

44. The apparatus of claim 42, wherein the digital encryption procedure is a public key encryption procedure.

45. The method of claim 42, wherein the sensor signals and the video signal are mixed.

46. The method of claim 45, wherein the video signal is modulated with a carrier signal and with an encrypted sensor signals.

47. Apparatus for recording sensor data with a video signal to protect the sensor data, the sensor data being contained in signals from one or more sensors, the apparatus comprising:
a compression circuit to compress the video signal;
a signal processing circuit to combine the compressed video signal and the signals from the one or more sensors and produce a digital signal therefrom;
an encryption circuit to encrypt the digital signal and produce an output signal therefrom; and a recorder to record the output signal on a recording medium.

48. The apparatus of claim 47, wherein the compression circuit includes:
a digitizer to digitize the video signal to produce video digital signals therefrom; and a compression circuit to compress the video digital signals in accordance with a digital compression procedure and produce the compressed video signal.

49. The apparatus of claim 48, wherein the compression circuit includes;
an encryption circuit to encrypt the digital signals in accordance with a digital encryption procedure.

50. The apparatus of claim 49, wherein the encryption circuit includes a public key encryption circuit to encrypt the digital signals in accordance with a public key encryption procedure.

51. The apparatus of claim 47, wherein the video signal and the signals containing the sensor data are digital signals, the compression circuit includes a digital compression circuit to compress the digital signals in accordance with a digital compression procedure, the signal processing circuit digitally combines the video signal and the encrypted signals, and the encryption circuit encrypts the digital signal in accordance with a digital encryption procedure.

52. Apparatus for retrieving sensor data originally produced by one or more sensors, the sensor data being encrypted with a video signal to produce a recorded signal that protects the sensor data and being contained in signals from one or more sensors, the apparatus comprising:

a play-back circuit to play back the recorded signal to produce a played-back signal;
a decryption circuit to decrypt the played-back signal to produce a video signals and one or more sensor signals containing data originally produced by one or more sensors;
a logic circuit to determine whether any of the one or more sensor signals are digital signals; and a signal processing circuit to process the one or more sensor signals to produce the sensor data.

53. The apparatus of claim 52, wherein at least one of the sensor signals is a digital signal that has been encrypted with a digital encryption procedure.

54. The apparatus of claim 53, wherein the digital encryption procedure is a public key encryption procedure.

55. The method of claim 53, wherein the signals processing circuit includes a decompression circuit to decompress any digital sensor signals.

56. The apparatus of claim 55, wherein the video signal is modulated with a carrier signal and with an encrypted sensor signal.

57. Apparatus for recording sensor data with a video signal, the sensor data being contained in signals from one or more sensors, the apparatus comprising:
a distinction circuit to determine which of the signals from the one or more sensors are analog sensor signals and which of the signals from the one or more sensors are digital sensor signals;

a first conversion circuit to convert the data in the analog sensor signals to one or more first digital signals;
an encryption circuit to encrypt the digital sensor signals and the one or more first digital signals to produce second digital signals;
a second conversion circuit to convert the second digital signals to first analog signals; and a recorder to record the video signal and the first analog signals on a recording medium.

58. The apparatus of claim 57, wherein the encryption circuit comprises:
a digital encryption circuit to encrypt the digital sensor signals in accordance with a digital encryption procedure.

59. The apparatus of claim 58, wherein the digital encryption circuit includes a public key encryption circuit to encrypt the digital signals in accordance with a public key encryption procedure.

60. The apparatus of claim 57, wherein the second conversion circuit includes a compression circuit to compress the second digital signals in accordance with a digital compression procedure.

61. The apparatus of claim 57, wherein the second conversion circuit includes a mixer to mix the video signal and the first analog signal.

62. The apparatus of claim 57, wherein the second conversion circuit includes a modulation circuit to modulate carrier signal with the video signal and with the first analog signal.

63. Apparatus for retrieving sensor data originally produced by one or more sensors, the sensor data being encrypted with a video signal to produce a recorded signal that protects the sensor data and being contained in signals from one or more sensors, at least one of the sensors producing an analog signal, the apparatus comprising:
a play-back circuit to play back the recorded signal to produce a played-back signal;
a decryption circuit to decrypt the played-back signal to produce a video signal and one or more sensor signals containing data originally produced by one or more sensors:
a logic circuit to determine whether any of the on sensor signals are digital signals; and a signal processing circuit to process the one or more sensor signals to produce the sensor data, including converting the one or more sensor signals to produce a corresponding analog signal.

64. The apparatus of claim 63, wherein at least one of the sensor signals is a digital signal that has been encrypted with a digital encryption procedure, and the signal processing circuit includes a decryption circuit to decrypt the digital signal accordion to the digital encryption procedure.

65. The apparatus of claim 64, wherein the digital encryption procedure is a public key encryption procedure.

66. The apparatus of claim 65, wherein the decryption circuit decompresses any digital sensor signals.

67. The apparatus of claim 66, wherein the video signal is modulated with a carrier signal and with an encrypted sensor signal.

68. Apparatus for recording sensor data with a video signal to protect the sensor data, the sensor data being contained in signals from one or more sensors, the apparatus comprising:
means for encrypting the signals from the one or more sensors;
means for combining the video signal and the encrypted signals to produce an output signal; and means for recording the output signal on a recording medium.

69. Apparatus for recording sensor data with a video signal to protect the sensor data, the sensor data being contained in signals from one or more sensors, the apparatus comprising:
means for compressing the video signal to produce a compressed video signal;
means for combining the compressed video signal and the signals from the one or more sensors to produce a digital signal;
means for encrypting the digital signal to produce an output signal; and means for recording the output signal on a recording medium.

70. Apparatus for recording sensor data with a video signal to protect the sensor data, the sensor data being contained in signals from one or more sensors, the apparatus comprising:

means for determining which of the signals from the one or more sensors are analog sensor signals and which of the signals from the one or more sensors are digital sensor signals;
first means for converting the data in the analog sensor signals to one or more first digital signals;
means for encrypting the digital sensor signals and the one or more first digital signals to produce second digital signals;
second means for converting the second digital signals to first analog signals; and means for recording the video signal and the first analog signals on a recording medium.

71. A method for recording sensor data with a video signal, the sensor data being contained in signals from one or more sensors, the method comprising the steps of:
a) encrypting the signals from the one or more sensors to produce an output signal; and b) recording the output signal and the video signal on a recording medium.

72. Apparatus for recording sensor data with a video signal, the sensor data being contained in signals from one or more sensors, comprising:
an encryption circuit to encrypt the signals from the one or more sensors to produce an output signal; and a recorder to record the output signal and the video signal on a recording medium.

73. A method for recording sensor data with a video signal in a motor vehicle, the sensor data being contained in signals from one or more sensors in the motor vehicle, the method comprising the steps of:

a) encrypting the signals from the one or more sensors;
b) combining the video signal and the encrypted signals to produce an output signal; and c) recording the output signal on a recording medium.

74. Apparatus for recording sensor data with a video signal in a motor vehicle, the sensor data being contained in signals from one or more sensors in the motor vehicle, the apparatus comprising:
an encryption circuit to encrypt the signals from the one or more sensors;
a circuit to combine the video signal and the encrypted signals and produce an output signal therefrom; and a recorder to record the output signal on a recording medium.