Abstract: In an authentication apparatus, coordinates input from a coordinate detector via a plurality of discontinuous holes or openings, cutouts or marks provided on a member which is used to specify the coordinates are detected, and an authentication is made based on a comparison result of the detected coordinates and a plurality of registered coordinates.

Abstract: Cryptographic methods are disclosed, which allow a prover party, who holds a number of secrets, to demonstrate satisfiable formulas of propositional logic, wherein the atomic propositions are linear relations between the secrets. The demonstration reveals no more information than is contained in the formula itself. Some implementations allow an unlimited number of such demonstrations to be made, without revealing any additional information about the secrets, whereas other implementations ensure that the secrets, or some of the secrets, will be revealed, if a demonstration is performed more than a predetermined number of times. The demonstrations may be zero-knowledge proofs, or signed proofs.

Abstract: A quantum state or qubit is transmitted from a sender to receiver using a quantum teleportation. For this purpose, first, second and third photons are successively produced from a laser source. The first photon is modified in polarization according to encoded information to be sent. The second and third photons are mutually quantum-mechanically correlated and shared by the sender and receiver, respectively. The sender measures the polarized states of the coincidentally appearing first and second photons and transmits measurement outcomes to the receiver via classical communication. The receiver recovers information of the first photon from the third photon based on his measurement and the measurement outcomes transmitted by the sender.

Abstract: A data converting unit includes a key adding unit for performing an arithmetic addition modulo 232 for input data F and subkey data Ki and outputting the outcome as data G, and a data substituting unit for performing an exclusive-OR operation for corresponding bits in data Rot7(G) obtained by shift-rotating the data G by 7 bits toward higher-order bit positions, data Rot1(G) obtained by shift-rotating the data G by 1 bit toward higher-order bit positions, and the data G itself.

Abstract: A method and apparatus for cryptographically transforming an input block into an output block. The input block has a first block size and is partitionable into a plurality of input subblocks having a second block size that is a submultiple of the first block size. To encrypt or decrypt, the input subblocks are passed through respective first substitution functions controlled by one or more keys to generate a first plurality of modified subblocks. The first plurality of modified subblocks are then passed through a mixing function to generate a second plurality of modified subblocks, each of which depends on each of the first plurality of modified subblocks. Finally, the second plurality of modified subblocks are passed through respective second substitution functions controlled by one or more keys to generate a plurality of output subblocks that are combinable into an output block.

Abstract: In elliptic curve processing systems, information is typically processed to yield elliptic curve data points, with X and Y coordinates each represented by N bits, N typically being 160 or more. Valid Y coordinates must satisfy a quadratic equation for any given X coordinate, such that any Y data may be represented by its corresponding X coordinate and a single additional byte or bit. In accordance with this disclosure, a vector t is chosen for which the dot product between t and any X coordinate is equal to a constant. The vector t is used in a compression mode of the preferred embodiment to select a bit position in X coordinate data with the X bit at that location being discarded and the Y coordinate information being stored in its place. As a result, an extra byte of data is not needed and any elliptic curve data point may be represented by N bits only.

Abstract: Watermark data is encoded in a digitized signal by forming a noise threshold spectrum which represents a maximum amount of imperceptible noise, spread-spectrum chipping the noise threshold spectrum with a relatively endless stream of pseudo-random bits to form a basis signal, dividing the basis signal into segments, and filtering the segments to smooth segment boundaries. The data encoded in the watermark signal is precoded to make the watermark data inversion robust and is convolutional encoded to further increase the likelihood that the watermark data will subsequently be retrievable notwithstanding lossy processing of the watermarked signal. Watermark data is encoded in a basis signal by division of the basis signal into segments and inverting the basis signal in segments corresponding to watermark data bits with a first logical value and not inverting the basis signal in segment corresponding to watermark data bits with a different logical value.

Abstract: A method and system for enabling the use of a single client certificate to be used in SNA communications to ensure security such that the certificate cannot be intercepted and reused yet still allowing the use of a single certificate for multiple applications. This avoids the need for a connected trusted third party or a multiplicity of user id and password pairs.

Abstract: A process is described in which a user enters ID and password information at a network client computer terminal. This information is combined with an asymmetric key stored in a persistent storage directly accessible to the client's computer terminal. This "combined" information is communicated through a communication network to one or more server computers for authentication of the client. A similar identification and authentication process may be used to authenticate the server computer. Upon authentication of the client, the server provides the client computer with three symmetric keys, in encrypted format. The first key is for encrypting and decrypting persistent information associated with the client computer's control program. The second key is used to encrypt and decrypt persistent information associated with the login ID. The third key is used to encrypt and decrypt communication between the client computer and the server computer.