Process and apparatus for authenticating the signature of a signed message
First Claim
1. A process for authenticating the signature of a message sent by a transmitting device to a receiving device via a transmission path, comprising automatically computing at the transmitting device a signature of a message to be transmitted by using a signature-computing program which takes into account the entire contents of the message to be transmitted and a secret key which is unknown to both a sender and a recipient of the massage;
- transmitting the message and signature to the receiving device;
automatically recomputing at the receiving device a signature of the received message by using another signature-computing program which is the same as said first-mentioned signature-computing program, said other signature-computing program taking into account the entire contents of the received message and said secret key;
automatically comparing the signature of the received message with the signature recomputed at the receiving device; and
indicating to the recipient of the message in response to said comparing only whether the signature of the received message and the recomputed signature are identical or different, while preventing the recipient from access to the value of the recomputed signature.
4 Assignments
0 Petitions
Accused Products
Abstract
A process and a device for authenticating the signature of a signed message includes a nominal signature card (1a) coupled to a transmitting device 1 which sends signed messages. The card (1a) includes at least one memory (5) in which there are secretly prerecorded at least one secret key (S) and one program (P) which automatically processes the signature of a message (M), as well as circuits (6) for computing the signature (SG). A control card (3b), which is not nominal, is coupled to a device (3) for receiving signed messages. The card (3b) includes at least one memory in which there are secretly prerecorded at least the secret key (S) and the program (P) for recomputing via processing circuits (15) the signature (SG) of the received message (M).
-
Citations
14 Claims
-
1. A process for authenticating the signature of a message sent by a transmitting device to a receiving device via a transmission path, comprising automatically computing at the transmitting device a signature of a message to be transmitted by using a signature-computing program which takes into account the entire contents of the message to be transmitted and a secret key which is unknown to both a sender and a recipient of the massage;
-
transmitting the message and signature to the receiving device; automatically recomputing at the receiving device a signature of the received message by using another signature-computing program which is the same as said first-mentioned signature-computing program, said other signature-computing program taking into account the entire contents of the received message and said secret key; automatically comparing the signature of the received message with the signature recomputed at the receiving device; and indicating to the recipient of the message in response to said comparing only whether the signature of the received message and the recomputed signature are identical or different, while preventing the recipient from access to the value of the recomputed signature. - View Dependent Claims (2, 3, 4, 5, 6)
-
-
7. Apparatus for authenticating a message sent by a transmitting device to a receiving device via a transmission path, the transmitting device comprising means for automatically computing a signature of a message to be transmitted and for transmitting the computed signature with the message to the receiving device, said computing means comprising first processing means controlled by a first signature-computing program for computing the signature of the message to be transmitted in accordance with the contents of the message and a secret key which is unknown to both a sender and a recipient of the message;
- and a receiving device comprises means for automatically recomputing the signature of a received message, the recomputing means comprising second processing means controlled by a second signature-computing program which is the same as said first signature-computing program for recomputing the signature in accordance with the contents of the received message and said secret key;
means for automatically comparing the signature of the received message with the signature recomputed by said recomputing means; and
means responsive to said comparing means for indicating to the recipient of the message only whether the signature of the received message and the recomputed signature are identical or different, while preventing the recipient access to the value of the recomputed signature. - View Dependent Claims (8, 9, 10, 11, 12, 13, 14)
- and a receiving device comprises means for automatically recomputing the signature of a received message, the recomputing means comprising second processing means controlled by a second signature-computing program which is the same as said first signature-computing program for recomputing the signature in accordance with the contents of the received message and said secret key;
Specification