Process and system for transmission of signed messages
AssigneeCompagnie Internationale pour l'Informatique Cii-Honeywell Bull
InventorJean H. Mollier
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Abstract
The transmission of signed messages occurs between a transmitter (1) and a receiver (3) connected by a transmission line system (2). The transmitter (1) and the receiver (3) respectively comprise a coding device 7 and a decoding device 11. Means 4 situated at the transmitter supply a signature SG as a function of the message M which is to be transmitted. The message associated with its signature, as well as a common key E, are transmitted by the transmitter towards the receiver after coding by means of an intrinsic key R.sub.1. Upon being received, the message M linked with its signature SG is decoded by means of an intrinsic key R.sub.2 determined at the receiver location in such manner as to establish equality between intrinsic keys R.sub.1 and R.sub.2.
Claims49
A process for the transmission of signed messages M between a transmitter and a receiver connected via a transmission line system, the transmitter including a coding device and the receiver including a decoding device, said process comprising:
- calculating a signature SG at the transmitter location as a function of the message M which is to be transmitted and as a function of a secret code J which enables the subsequent certification of the signature;
- linking the message with the signature thus obtained;
- generating at the transmitter location a common key E;
- calculating at the transmitter location as a function of at least the common key E an intrinsic coding key R.sub.1 and employing the intrinsic coding key R.sub.1 to encode the linked message and signature;
- causing the transmitter to transmit the common key E and the encoded message and signature;
- and
- calculating at the receiver location as a function of at least the common key E an intrinsic decoding key R.sub.2 and employing the intrinsic decoding key R.sub.2 to decode the coded message and signature.
A system for the transmission of signed messages M between a transmitter and a receiver interconnected by a transmission line system, the transmitter and receiver respectively including a coder and a decoder for coding and decoding each message M and its signature, said system comprising:
- means located at the transmitter for calculating a signature SG as a function of the message M which is to be transmitted and as a function of a secret code J which enables the subsequent certification of the signature;
- means located at the transmitter for linking the message M which is to be transmitted with the calculated signature;
- means located at the transmitter for generating a common key E;
- means located at the transmitter for calculating an intrinsic coding key R.sub.1 as a function of at least the common key E for use by the coder to encode the linked message M and signature SG;
- means in the transmitter for transmitting the common key E and the encoded message and signature to the receiver;
- and
- means located at the receiver for calculating an intrinsic decoding key R.sub.2 as a function of at least the common key E for use by the decoder to decode the encoded message M linked with its signature SG.
Dependencies are inferred from the claim text.