Abstract: A finite field inverse circuit (600) for use in an elliptic curve processor (12). The finite field inverse circuit (600) comprises a control circuit (610) and a data circuit (660). The data circuit (610) comprises a data multiplexer (668) for coupling the contents of one of three registers (662, 664, 680) to a finite field arithmetic logic unit (122). A first plurality of bits representing the finite field element to be inverted is initially loaded into a first one of the three registers. The control circuit (660) comprises a shift register (614) suitable for storing a second plurality of bits representing a size of the finite field element to be inverted.

Abstract: A terminal adapter accommodates a data terminal device having an interface such as an RS-232C interface or the like in an ISDN. In response to an authentication request according to the CHAP from a peer, a first converting/transmitting unit transmits an authentication request according to the PAP to the data terminal device. For authentication in a B1 channel, the data terminal device transmits an ID and a password according to the PAP to the terminal adapter. A first transmitting unit encrypts the transmitted password and returns the encrypted password to the peer. A receiving/holding unit holds the ID and the password which have been transmitted. For authentication in the B1 channel, a second transmitting unit encrypts the password that has been held, and transmits the encrypted password to the peer.

Abstract: An authentication system comprising a medium having a plurality of elements, the elements being distinctive, detectable and disposed in an irregular pattern or having an intrinsic irregularity. Each element is characterized by a determinable attribute distinct from a two-dimensional coordinate representation of simple optical absorption or simple optical reflection intensity. An attribute and position of the plurality of elements, with respect to a positional reference is detected. A processor generates an encrypted message including at least a portion of the attribute and position of the plurality of elements. The encrypted message is recorded in physical association with the medium. The elements are preferably dichroic fibers, and the attribute is preferably a polarization or dichroic axis, which may vary over the length of a fiber.

Abstract: Implemented preferably within a digital camera, an electronic device is used to prevent a captured data clip from being fraudulently altered without detection. The electronic device performs "time-bracketing" and may contain cellular phone circuitry to establish wireless communication to receive a state value used to preserve data integrity when time-stamping is performed in combination.

Abstract: Each transmission frame within a spread spectrum communications system relating to synchronization code transmission is divided into a plurality of slots. Each of the slots includes a primary (pilot) code c.sub.p and a secondary (combined) code c.sub.s/lci that includes information identifying or indicative of both a frame timing and a scrambling code for synchronization. This information concerning frame timing and scrambling code may be encoded in the combined code c.sub.s/lci itself, as well as in the modulation values of the sequences of plural combined codes within a frame. Alternatively, the information is encoded in the sequence of plural combined codes c.sub.s/lci transmitted in each frame, as well as in the modulated values of the sequences of plural combined codes within a frame. As yet another alternative, the information is encoded in the timing of the combined code c.sub.s/lci transmission within each slot of the frame relative to its associated primary code c.sub.p.

Abstract: A method and apparatus for verifiably providing key recovery information to one or more trustees in a cryptographic communication system having a sender and a receiver Each communicating party has its own Diffie-Hellman key pair comprising a secret value and corresponding public value, as does each trustee The sender non-interactively generates from its own secret value and the public value held by the receiver a first shared Diffie-Hellman key pair comprising a first shared secret value, shared with the receiver but not with any trustee, and a corresponding public value. For each trustee, the sender then non-interactively generates an additional shared secret value, shared with the receiver and the trustee, from the first shared secret value and the public value corresponding to the secret value held by the trustee. The sender uses the additional shared secret value to encrypt recovery information for each trustee, which is transmitted to the receiver along with the encrypted message.

Abstract: A method for accessing at least a portion of the data on a microprocessor card, such as a Subscriber Identity Module (SIM) card having at least one freely accessible card number for use with mobile phones. A separate master card uses a self-contained key and encryption algorithm together with the accessible SIM card number to generate a first identification number that is communicated to and stored on the SIM card during initial programming of the SIM card. When access to data stored on the SIM card is thereafter required, a second identification number is calculated in the same manner, is communicated to the SIM card, and is compared on the SIM card with the stored first identification number. Access to the data stored on the SIM card is granted only when the first and second identification match.

Abstract: The invention consists of attaching or embedding a "TIRIS" transponder (or other RF or IR or barcode or other identifying device) physically into the center of the proposed DVD disk. Within the memory of the transponder, both a predetermined address and a code word are preprogrammed into the transponder at the manufacturing level of the media product. The media player not only comprises functionality to play the disk, but also comprises the functionality to transmit an interrogation signal to the transponder, and then to receive the transponder response signal. Therefore, once a disk is input to a media player, the interrogation portion of the media player transmits an interrogation signal to the transponder located on the disk. Thus once empowered with the interrogation signal, the transponder accesses the predetermined address and the code word from it's memory.