Abstract: Disclosed herein are an apparatus and method for anonymity-based authentication and key agreement capable of providing a communication message binding property. The apparatus includes a signature verification unit and a binding checking unit. The signature verification unit receives a plurality of messages, each carrying a signature including link information of a sender, and verifies the signature of each of the plurality of messages. The binding checking unit, if it is determined by the signature verification unit that the signature is valid, determines whether the plurality of messages has been sent by an identical sender based on the link information of the signature.

Abstract: Disclosed herein are an apparatus and method for anonymity-based authentication and key agreement capable of providing a communication message binding property. The apparatus includes a signature verification unit and a binding checking unit. The signature verification unit receives a plurality of messages, each carrying a signature including link information of a sender, and verifies the signature of each of the plurality of messages. The binding checking unit, if it is determined by the signature verification unit that the signature is valid, determines whether the plurality of messages has been sent by an identical sender based on the link information of the signature.

Abstract: There is provided a channel encoder having convolutional encoders concatenated in parallel or in series. The channel encoder includes a first encoder for encoding input information bits, an interleaver having a memory and an index generator, for modifying the order of the information bits in a predetermined method, a second encoder for encoding the output of the interleaver, first and second terminating devices for terminating frames of input and output information bits of the first and second encoders, a tail bit generator for storing tails bits used in frame termination, and a controller and a switch for controlling the above procedure.

Abstract: The present invention relates to an improved method for performing modular exponentiation to a fixed base element. The method includes exponentiating a first digital input signal g by a second digital input signal R, where g is a fixed signal unique to a cryptographic system and R is a randomly generated digital signal, to compute a third digital signal g.sup.R. The exponentiating includes pre-computing and storing a plurality of values depending only upon the fixed signal g in a plurality of memory locations within a computing device and then speeding up the computation of g.sup.R using the stored values. The invented exponentiation method can substantially reduce the amount of computation required to compute the value for g.sup.R. Exponentiation methods according to embodiments of the present invention may be used in a variety of cryptographic systems, e.g., Schnorr identification scheme, Digital Signature Standard (DSS), and Diffie-Hellman key agreement scheme, etc.