WO2007042393A1

WO2007042393A1 - Method for generating a digital message encryption key according to a pilot voice signature

Info

Publication number: WO2007042393A1
Application number: PCT/EP2006/066751
Authority: WO
Inventors: Matthieu Borel; Nicolas Rossi; Michel Subelet
Original assignee: Thales
Priority date: 2005-10-07
Filing date: 2006-09-26
Publication date: 2007-04-19
Also published as: FR2891970A1; FR2891970B1

Abstract

The invention relates to a method for generating the encryption key of a digital communication message, which is transmitted by an aircraft pilot, according to the pilot voice signature. An onboard database stores the signatures of the aircraft pilots enabling them to transmit messages therefrom. The inventive method consists in producing a pilot signature, in determining whether the produced signature is recorded to the signature database, in the case, when said signature is stored in the database, in generating an encryption key according to the produced signature for encrypting the digital messages transmitted by the aircraft pilot and in communicating the signature via a communication network, and when the produced signature is not stored in the database, in inhibiting the digital communication message transmission by the aircraft pilot.

Description

Method for generating a digital message encryption key from a pilot's voice signature

The present invention relates to a method for generating a digital communication message encryption key issued by an aircraft pilot from a voice signature of the pilot.

As part of the CNS-ATM (Communication Navigation Surveillance Air Traffic Management) deployment, the aeronautical authorities represented by NCAO (International Civil Aeronautical Organization) have defined specific recommendations for the implementation of future air traffic management applications (ATC). or Air Traffic Control). However, the opening of civil aeronautical communications to "mainstream" digital technologies makes these exchanges more vulnerable to malicious individuals. The espionage of the exchanges, the falsification of the exchanged messages, constitute the main threats. This is why mechanisms are put in place to contribute to the safety of edge / ground communications by preventing unauthorized access to exchanged data.

Almost all the techniques implemented in safety systems are based on the use of encryption algorithms that are public. The robustness of these techniques is based on the choice of encryption keys that make it possible to perform encryption among a set of possible encryptions. The algorithms in question operate by exchange of private keys, or using public / private keys, in both cases the Achilles heel of the security systems lies in the confidentiality of the key used. Unlike the algorithm, which remains fixed at the scale of several years, it is desirable that the encryption key is changed quite frequently. The periodicity of this change must be less than the supposed "break" duration of the algorithm, the longer and more complex the key, and the greater the workload to "break" the system. The management of encryption keys and their updating is a critical operation of security systems.

A first solution for injecting encryption keys into on-board communication management systems on aircraft consists in entrusting the loading of the keys to the maintenance teams. This solution has the advantage of being an automated and renewable procedure but has the disadvantage of expanding the circle of people with access to encryption keys. A second solution to the problem of managing encryption keys is to have the drivers manually load an encryption key into the communications management system before sending a first message. By doing so, the distribution of the key is extremely restricted. But this operation is quickly tedious and represents a source of potential errors, since an encryption key may consist of a sequence of several hundred bytes.

The present invention overcomes the disadvantages of the two solutions presented above. Its purpose is to automatically generate an encryption key from the acquisition of a signature specific to the driver, this signature uniquely identifying and unique driver.

For this purpose, the subject of the invention is a method for generating a digital communication message encryption key issued by an aircraft pilot on a communication network, a database embedded on the aircraft comprising pilot signatures. authorized to send messages from the aircraft, characterized in that it comprises the following steps:

- develop a pilot's signature; - determine the membership of the elaborate signature in the database of signatures;

- If the database contains the elaborate signature, generate an encryption key from the signature developed to encrypt the digital messages issued by the pilot of the aircraft, and communicate the signature on the communication network.

if the database does not contain the elaborated signature, inhibit the transmission of digital communication message by the pilot of the aircraft. Other features and advantages of the invention will appear on reading the detailed description which follows and which is given with reference to the appended drawings in which:

- Figure 1 schematically shows the architecture of a security system associated with a communications management system;

FIG. 2 represents a flowchart of the method according to the invention.

FIG. 1 represents a SYS security system 1 associated with a CMS 15 communication management system. The SYS security system and the CMS communication management system are embedded on the same aircraft, the SYS system supplies the management system with communication CMS the means to perform the encryption of the communication messages issued by a pilot of the aircraft for example, the messages are issued by the pilot to a ground-based air traffic control authority.

The SYS security system comprises a GSIG signature generation device 12, a BDDS signature database 1 1, and a GCLE encryption key generation device 10.

The GSIG signature generation device generates a signature that is specific to each pilot from personal data provided by the pilot. This signature is for example a voice signature that is to say a signature that is developed from the pronunciation by the driver of a predefined sentence. The voice of the driver pronouncing the predefined sentence is for example recorded by the GSIG device on a digital medium.

The BDDS signature database contains signatures of all drivers authorized to send messages over the communication network through the CMS communication management system. The content of the BDDS signature database is periodically updated by maintenance teams. The security system SYS can on request determine the membership of a signature developed by the GSIG signature generation device to the BDDS signature database.

When the security system has determined the membership of the signature in the database BDDS, it transmits the signature to the device GCLE key generation and the CMS communication management system.

From the signature, the device GCLE generates an encryption key which is transmitted to the communication management system CMS. The SGC system uses the key, which can be a sequence of one to several hundred bytes, to encrypt all messages emitted by the pilot of the aircraft and to decrypt the received messages.

The communication management system SGC sends the signature on the communication network before a first transmission of communication message by the pilot. Thus, receiving stations connected to the network establish the identity of the pilot retrieve elements to decrypt the messages sent by the pilot of the aircraft and use these same elements to encrypt the messages sent back.

FIG. 2 represents a flowchart of the method for generating an encryption key according to the invention.

Before issuing a communication message from a communication network, all pilots must identify themselves by providing personal data to a SYS security system. Advantageously, the development of the pilot signature is performed at the initialization of communications on the communication network.

Advantageously, the signature is developed from the pronunciation by the pilot of a predefined sentence. In this case, the driver pronounces the predefined sentence in front of a digital voice data recording means forming part of the SYS security system.

From this personal data, a GSIG signature generation device generates a signature specific to the pilot. Whenever the SYS security system prepares a new signature, it ensures that it is part of the signatures stored in a security system signature database. The development of the pilot's signature constitutes a step 100 of the method according to the invention.

Advantageously, the determination of the membership of the elaborated signature in the database of signatures is carried out at the initialization of the communications on the communication network, the determining the membership of the signature in the database BDDS constitutes a step 101 of the method according to the invention.

When the SYS security system has established the membership of the signature in the database BDDS, it authorizes the transmission of encrypted digital communication messages on the communication network. To do this, the SYS security system generates an encryption key (step 102), from the elaborate signature, which is used by the CMS management system to encrypt all the messages sent by the driver on the network. communication. At the initialization of the communications on the communication network, in other words, before a first sending by the pilot of a communication message, the elaborated signature is sent (step 103) by the security system on the communication network. Receiving stations connected to the communication network comprise a signature database associating the signatures of the persons authorized to send messages on the communication network and means making it possible to decrypt the encrypted messages that they transmit.

When the signature is absent from the signature database, the digital message transmission from the aircraft is inhibited on the communication network during a step 105.

Claims

1. A method of generating a digital communication message encryption key issued by an aircraft pilot on a communication network, a database embedded on the aircraft comprising pilot signatures authorized to send messages from the aircraft. aircraft, comprising the following steps:

- develop a pilot's signature;

- determine the membership of the elaborate signature in the database of signatures;

- if the database does not contain the elaborate signature, inhibit the transmission of digital communication message by the pilot of the aircraft, characterized in that the signature is developed from the pronunciation by the pilot of a sentence predefined.

2. Method according to claim 1 characterized in that the development of the signature of the driver is performed at the initialization of communications on the communication network.

3. Method according to claim 1 characterized in that the determination of the membership of the elaborate signature to the database of signatures is performed at the initialization of communications on the communication network.

4. Method according to claim 1 characterized in that the messages are sent to a ground based air traffic control authority.