Showing papers on "Multiple encryption published in 1989"

Data encryption key failure monitor

Abstract: An encryption key, required to encrypt and decrypt data according to a predefined algorithm is usually retained in a volatile memory device Detection of loss of the key or corruption of the key is frequently possible only be means of the encryption circuit itself testing the key Automated and repetitive testing of encryption keys by means of a processor or a control circuit periodically requesting the encryption circuit to test an encryption key minimizes data loss and system down time due to corrupted or lost keys

Encryption with subsequent source coding

Abstract: The invention relates to a process for encryption and source coding of a sequence of information which preferably relates to moving pictures. According to the invention, encryption processes are proposed which make possible subsequent source coding. The sequence of information is divided into blocks and encryption can take place by global permutation of blocks and/or local rotation, reflection and inversion of blocks. According to another aspect of the invention, encryption can take place by means of an area-filling curve.

Decryption device with variable clock

Abstract: A decryption device wherein an encryption/decryption module can be operated at various clock speeds, and wherein an associated processor controls these clock speeds depending upon the moment to moment processing interrelationship between the encryption/decryption module and the processor. In particular, when loading a new key into the encryption module, or when utilizing the encryption module to decrypt an encrypted new key, the processor alters the usual clock rate for the encryption module.

A rotor device for periodic and random-key encryption

Abstract: A simple rotor device is described which can generate two levels of encryption security: periodic encryption to any key length, and random-key encryption. The latter depends on what appears to be a useful and widely-available source of at least pseudorandom numbers: the telephone directory.

Public-key encryption algorithm incorporating error detection

Abstract: Owing to their mathematical properties, quadratic residues have been used successfully in designing a number of cryptographic applications, such as oblivious transfer protocol and coin flipping protocol. The authors propose an encryption scheme based on quadratic residue theory. In particular, they incorporate the encrypting procedure and error-detecting code into a complete communication system.

2-Bit, chained, probabilistic encryption scheme

Abstract: In this letter we present a new probabilistic encryption algorithm based on the scheme proposed by Jingmin and Kaicheng in 1988. This algorithm utilises the public key concept and recursively encrypts two bits at a time. The message bit expansion is very low and is the same as in their scheme. At the same time, this new scheme is twice as fast.