Abstract: A process for realizing mappings between codewords of two distinct (N,K) Reed-Solomon codes over GF(2.sup.J) having selected two independent parameters: J, specifying the number of bits per symbol; and E, the symbol error correction capability of the code, wherein said independent parameters J and E yield the following: N=2.sup.J -1, total number of symbols per codeword; 2E, the number of symbols assigned a role of check symbols; and K=N-2E, the number of code symbols representing information, all within a codeword of an (N,K) RS code over GF(2.sup.J), and having selected said parameters for encoding, the implementation of a decoder are governed by: 2.sup.J field elements defined by a degree J primitive polynomial over GF(2) denoted by F(x); a code generator polynomial of degree 2E containing 2E consecutive roots of a primitive element defined by F(x); and, in a Berlekamp RS code, the basis in which the RS information and check symbols are represented.

Abstract: Each access attempt transmitted to an authentication agency causes the agency to produce a request identifier unique to that request. The request identifier is transmitted back to the authentication code generator of the user initiating the access attempt, and to an authentication code generator in the agency. The agency also retrieves a user identifier from a database and sends it to its authentication code generator. Both the user's authentication code generator and the agency's authentication code generator independently combine, through identical or complementary transformations, the user identifier and the request identifier to form a user authentication code and an agency authentication code. The two authentication codes are presented by a comparator, which issues a permit signal only if the comparison indicates a match between the two authentication codes. The permit signal is transmitted to a transaction control device to permit the transaction to proceed.

Abstract: A memory system is provided, of the type which includes an error-correcting circuit that detects and corrects errors, which more efficiently utilizes the capacity of a memory formed of groups of binary cells whose states can be inadvertently switched by ionizing radiation. Each memory cell has an asymmetric geometry, so that ionizing radiation causes a significantly greater probability of errors in one state than in the opposite state (e.g., an erroneous switch from "1" to "0" is far more likely than a switch from "0" to "1"). An asymmetric error-correcting coding circuit can be used with the asymmetric memory cells, which requires fewer bits than an efficient symmetric error-correcting code.

Abstract: A verifier for use in a personal identification system of the type in which a generator receives at least a personal account number (PAN) and a secret personal identification number (PIN) and based thereon produces digits A.sub.i 's which are present in a feedback shift register (FSR) A and digits C.sub.i 's present in a feedback shift register (FSR) C respectively. The A.sub.i 's and C.sub.i 's are mapped into D.sub.i 's which represent digits of an Offset Number which together with the PAN are recorded on the magnetic stripe of a card. To use the cards the Offset Number and the PAN are read off therefrom and an intended user enters a secret PIN. In the verifier, the PIN is operated upon to produce C.sub.i 's and the PAN is operated upon to produce A.sub.i 's. The latter together with the D.sub.i 's of the received Offset Number are mapped by a processer (201) to form C.sub.i.sup.c 's. These are compared with the C.sub.

Abstract: A personal identification system comprises a generator which generates an Offset Number which is recorded on the magnetic stripe of a card, together with the account number (PAN) of the person to whom the card is to be issued. The generator stores transformed digits of a sequence of digits (IN) which have been secretly entered by one or more officers of the card-issuing institution. To generate the Offset Number the PAN is entered and transformed before being stored to initialize a first feedback shift register. The person to whom the card is to be issued enters a chosen alphanumeric sequence (PIN) secretly known only to him. The PIN, after undergoing transformation is stored to initialize a second feedback shift register. When both registers have been initialized they are reinitialized by different parts of different digits of the transformed IN.

Abstract: A distributed processing telex switch having different levels of processor control to handle the calls between terminations connected to the exchange is disclosed. A common control processor occupies the highest level of processor control and function as the system-wide manager. Next below common control is a plurality of master control processors which function to switch the command data between common control and the lower levels of processor control, and to handle the conversation data generated by each of the terminations connected to the exchange. Each master control processor controls a predetermined number of termination from among all of the terminations connected to the exchange. Connected to each master control processor is a plurality of group control processors which control the flow of data to and from a second predetermined number of terminations from among the terminations controlled by each master control processor.

Abstract: A circuit for the systematic handling of conversation data from a calling party to a called party for use in a distributed processing telex exchange is disclosed. The customer terminations connected to the exchange are divided into a predetermined number of groups of terminations having a predetermined number of terminations in each group. Associated with each group of terminations is a frame memory which has memory capacity for storing a single bit of conversation data from every termination connected to the exchange. Associated with each frame memory is a vector memory which has a memory location associated with each termination in a group. Each vector memory location contains a frame memory address that addresses the location in frame memory containing the conversation data to be forwarded down to the termination associated with the current vector memory address.