Abstract: A computer implemented method for anonymous proximity tracing implemented by a plurality of participating devices. The method includes, upon detection by a first participating device of a respective current public key broadcast by a second participating device, at each of the first participating device and second participating device: i. computing a current shared secret; ii. computing first and second tokens parametrized with the current shared secret and a value relating to the first, and respectively second, participating devices; and iii. based on a sorting value, storing the first and second tokens in selected ones of first and second encounter token lists of the first and second participating devices; and selectively uploading at least part of one of the first encounter token list or the second encounter token list by a given participating device to a proximity management server.

Abstract: A key agreement system, method, and apparatus are provided. The method includes: generating, by a first device, a private-public key pair, sending a public key in the private-public key pair to a second device, and receiving a ciphertext and a commitment value; obtaining, by the first device, a first result, obtaining an original key based on a private key in the private-public key pair and the ciphertext, determining a second bit string based on some bits in the original key, calculating a second result based on the second bit string and the first result, and sending the second result to the second device; and receiving, by the first device, an opening value, performing authentication on the second device based on the opening value and the commitment value to obtain an authentication result, and generating a session key used to communicate with the second device.

Abstract: A key agreement system, method, and apparatus are provided. The method includes: generating, by a first device, a private-public key pair, sending a public key in the private-public key pair to a second device, and receiving a ciphertext and a commitment value; obtaining, by the first device, a first result, obtaining an original key based on a private key in the private-public key pair and the ciphertext, determining a second bit string based on some bits in the original key, calculating a second result based on the second bit string and the first result, and sending the second result to the second device; and receiving, by the first device, an opening value, performing authentication on the second device based on the opening value and the commitment value to obtain an authentication result, and generating a session key used to communicate with the second device.

Abstract: In a control system comprising control device adapted for, on the one hand, receiving signal indicating a first biometric datum (W), and, on the other hand, obtaining a second biometric datum captured (w?), at the level of the control device, the first and second biometric date are compared. Next, it is decided whether the first and second biometric data correspond on the basis of the comparison. Thereafter, at least a secret cryptographic key part (H(w)) is generated by applying cryptographic function to the first biometric datum.

Abstract: A cryptographic message signature method are provided, which have strengthened security. The method implements two sets of signature algorithms SA1={K1, S1, V1} and SA2={K2, S2, V2}, where Ki, Si and Vi are key generation algorithms, signature generation algorithms and signature verification algorithms, respectively. The method includes: a step of generating permanent keys using the algorithm K1, delivering a pair of private and public keys {sk1, pk1}; and, for at least one message m to be signed: a signature step including sub-steps. The sub-steps include: receipt of the message m to be signed; generation of an ephemeral key pair {sk2,pk2} using the algorithm K2; calculation, by the signature algorithm S2, of the signature s2 of the message m by the private key sk2; calculation, by the signature algorithm S1, of the signature c1 of the public key pk2 by the private key sk1; and providing the strengthened signature {s2, c1, pk2}.

Abstract: The invention concerns a method for guaranteeing certification of a user's public key by reducing requests to key-certifying appropriate authorities. More particularly, the invention concerns a method for managing a public key of a user capable of being implemented in an asymmetric cryptosystem. According to the invention, a certification, or validation of the correspondence between a public key and a user, is performed by a validating entity, a provider separate from the certifying authority via a validation step. The password is verifiable by the validating entity, but without the latter being aware of it.

Abstract: In a control system comprising control device adapted for, on the one hand, receiving signal indicating a first biometric datum (W), and, on the other hand, obtaining a second biometric datum captured (w?), at the level of the control device, the first and second biometric date are compared. Next, it is decided whether the first and second biometric data correspond on the basis of the comparison. Thereafter, at least a secret cryptographic key part (H(w)) is generated by applying cryptographic function to the first biometric datum.

Abstract: Cryptography-based methods and apparatus for secure information processing are disclosed that are particularly efficient in terms of the computational resources required, and thus implementable in mobile telephones, personal digital assistants (PDAs) or other lightweight processing devices. A setup procedure is performed to permit interactions of a designated type, e.g., secure mobile gaming interactions, to be carried out between participants, e.g., one or more players and a casino. A given participant initiates a particular interaction with another participant by sending to that participant initiation information based at least in part on one or more results of the setup procedure. The other participant in turn sends response information back to the given participant, and the interaction then continues with one or more rounds each involving one or more decisions committed to by each participant.

Abstract: A method for generating a cryptographic key by players in a dynamic group, where: 1) a first player U1 initiates an upflow to the next player, the upflow based on a random value x1, a random value v1, and “g”, a generator of a finite cyclic group where a computational solution to a Diffie-Hellman problem is hard; 2) each player after the first Up sends an upflow Flp, comprising information based on a random value xp, a random value vp, and the previous upflow Flp?1; 3) the last player Up sends a downflow Fln to all other players in the dynamic group, where the downflow Fln comprises information based on a random value xn, a random value vn, and the previous upflow Fln?1. New players may join the dynamic group in a similar fashion. Players may be removed from the dynamic group by adjusting the downflow to the remaining players. The dynamic group may be refreshed by adjusting the downflow to establish a new cryptographic key.

Abstract: Cryptography-based methods and apparatus for secure information processing are disclosed that are particularly efficient in terms of the computational resources required, and thus implementable in mobile telephones, personal digital assistants (PDAs) or other lightweight processing devices. A setup procedure is performed to permit interactions of a designated type, e.g., secure mobile gaming interactions, to be carried out between participants, e.g., one or more players and a casino. A given participant initiates a particular interaction with another participant by sending to that participant initiation information based at least in part on one or more results of the setup procedure. The other participant in turn sends response information back to the given participant, and the interaction then continues with one or more rounds each involving one or more decisions committed to by each participant.

Abstract: A process for the identification of a claimant by a verifier. The process is of the public key type, where the public exponent is equal to 3. The claimant draws at random a first exponent .alpha., calculates r=g.sup..alpha. mod n and transmits R=r.sup.3. The verifier draws at random a second exponent .beta., calculates t=g.sup..beta. mod n, calculates T=t.sup.3 mod n and h=H.sub.1 (Z), where H.sub.1 is a hash function, and calculates Z=R.sup.3 mod n. The verifier transmits to the claimant the numbers T and h. The claimant calculates Y=T.sup..alpha. mod n, verifies the result H.sub.1 (Y), calculates H=H.sub.2 (Y), where H.sub.2 is another hash function, calculates z=rS mod n, and transmits z and H. The claimant also has a secret number S equal to the modulo n cubic root of a number I deduced from its identity so that the number S verifies S.sup.3 =I mod n. The verifier verifies that H received is equal to H.sub.2 (Z) and that z.sup.3 is equal to RI mod n.