Abstract: A secure memory and processing system is disclosed for use in various types of communication devices. The secure processing system provides for the encryption and storage of sensitive data in a storage medium external to the secure processing system. The encrypted data is decrypted with encryption logic circuitry within the secure memory and transferred to a zeroizable memory for use by a host processor. The secure memory uses a laser-scribed encryption key coupled to encryption logic circuitry within the secure memory for encrypting and decrypting the sensitive information.

Abstract: A method for purchasing items over a non-secure communication channel uses a secure communication device. The secure communication device includes a host processor, a secure memory that includes a laser-scribed encryption key, and a non-secure memory for storing encrypted data. A user's sensitive data is encrypted within the secure memory using the laser-scribed encryption key and stored as encrypted data in the non-secure memory. An encrypted credit card number and an encrypted secret key is retrieved from the non-secure memory, the encrypted credit card and secret key are decrypted with the laser-scribed encryption key, the credit card number is encrypted with a session key, and the encrypted credit card number is transferred over the network to a destination such as an internet vendor.

Abstract: A system and method allows portable, encrypted data to be accessible through multiple hosts, including new hosts (14), without requiring a secure link to the new hosts. A split key encryption system encrypts (52) data and stores the encrypted data on a portable device (10). A split of the encryption key is stored (54) in the portable device (10), and another split of the key is stored (54) in a home host (12) . A password-modified key is then made (58) by combining a password with the encryption key. This password-modified key is then reduced (58), with one split being stored on the host (12) and another split stored on the portable device (10) . Data can be accessed with a new host (14) by transferring (78) the host password-modified split to the new host (14) and entering (80) the password into the portable device (10).

Abstract: An arbitrary repeating pattern detector (ARPD) detects short cycle patterns having a length of N or less, where N is an integer number. The ARPD obtains data symbols from a random number generator. ARPD may be implemented in a circuit or process which evaluates data symbols b.sub.1 -b.sub.2N. A mismatch detector compares symbols b.sub.I+J-1 with symbols b.sub.N+J for all combinations of I and J, where I and J are integer numbers in the range of 1-N, inclusive. For each value of I, an alternative detector determines whether at least one mismatch occurs at any value of J. If such a mismatch is detected, an alternative indication declares a mismatch at the corresponding value of I. A conjunction detector determines whether alternative indications for all values of I indicate mismatches. If a single match is found, a repeating pattern is declared.

Abstract: N redundant processors operating in functional lockstep synchronization for maintaining system integrity. Comparison and synchronization logic are connected between N processors in redundant configuration and peripheral devices. The comparison and synchronization logic act to insure that the redundant processors are performing the same read/write operations. Calculation or processing not requiring access to peripherals may take place in an asynchronous manner. Processors are halted from performing further operations until all appropriate read or write operations are synchronized. The processors are then allowed to proceed. An overall watchdog timer provides for detecting an error condition for non-responsive or lead responding processors.