Showing papers on "Multiple encryption published in 1992"

Method and apparatus for encryption, decryption and authentication using dynamical systems

Abstract: A method and apparatus provide encryption, decryption and authentication of messages using dynamical systems. The method and apparatus preferably operate on an information stream which may comprise message information, authentication information, and random or pseudo-random information. The initial secret keys of the system are a collection of dynamical systems, at least one of which is irreversible. These keys operate on states of the dynamical systems into which the message has been encoded. To initialize the encryption, a subset of the secret keys are selected to be current keys, and the desired message is encoded into the initial states. Encryption continues over a plurality of cycles. During each cycle the current keys are applied either backward or forward in time to their current states, over a plurality of sub-cycles. If during an encryption cycle an irreversible dynamical system is iterated in the backward direction, the choice of antecedent states may either be made randomly or according to information from the input information stream. After all encryption cycles have been performed, the current states of the dynamical system constitute the ciphertext. The ciphertext may then be decrypted by a method similar to the encryption method. In the preferred embodiment, random noise is diffused into the plaintext during encryption, and eliminated during decryption. The apparatus of encryption and decryption in the preferred embodiment operates with parallel hardware using only bit operations and table lookup; it may thus be made to operate in an exceedingly fast manner.

Dynamic encryption key selection for encrypted radio transmissions

Abstract: A radio (100) transmits and receives encrypted signals having unencrypted key identifiers, allowing other radios having the corresponding key identifiers and encryption keys to communicate with radio (100). Prior to transmitting an encrypted message, radio (100) selects a unique key identifier automatically and uses the corresponding encryption key to encrypt the message that will be transmitted. Radio (100) transmits the key identifier in an unencrypted format with the encrypted message in order to allow other radios to determine the encryption key used in encrypting the message. When receiving an encrypted message, radio (100) uses the predetermined process stored in the radio (100) to properly select the proper encryption key for use in decrypting the incoming message.

Domain-based encryption

Abstract: A domain-based encryption system which uses identical domains known only to the parties involved in the communication. An encrypted message is sent between communicating parties which consists of a stream of coordinates which locate specific points in the domains. The located points comprise a symbol set that forms the plaintext message.

Toggle cipher transmitted between interconnected networks, encryption unit and encrypted data communication device using a óoeuvre such a process.

Abstract: This is a message encryption method transmitted between networks interconnected via highways using a specified network protocol, including for example the Internet Protocol (IP), a data communication device between the Figures least two devices belonging to two different networks interconnected via highways using a specified network protocol, and an encryption apparatus implementing said method. The method is characterized in that it encrypts messages keeping clear the "header" of the message allowing its delivery via gateways.

Linking protection in Federal Standard 1045 HF radios using the data encryption standard

Abstract: A method of utilizing the Data Encryption Standard (DES) algorithm for linking protection in HF radios complying with Federal Standard 1045 is described. The unique DES encryption method, which permits a codebook type of encryption of 24-bit words, is explained in detail. Also discussed is the method used to integrate this encryption process with the Federal Standard 1045 automatic link establishment protocols. Processing speed requirements for the hardware and software used to implement this scheme are explained, and available DES devices that can support the described implementation are identified.