Data processing apparatus

Patent 5740251 Issued on April 14, 1998. Estimated Expiration Date:

April 25, 2015. Estimated Expiration Date is calculated based on simple USPTO term provisions. It does not account for terminal disclaimers, term adjustments, failure to pay maintenance fees, or other factors which might affect the term of a patent.

Abstract Claims Description Full Text

Patent References

Interactive security control system for computer communications and the like
Patent #: 4691355
Issued on: 09/01/1987
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Patent #: 5230020
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Algorithm independent cryptographic key management apparatus Patent #: 5341427
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Inventors

Application

No. 428364 filed on 04/25/1995

US Classes:

380/269, Having compression380/28PARTICULAR ALGORITHMIC FUNCTION ENCODING

Examiners

Primary: Gregory, Bernarr E.

Attorney, Agent or Firm

Oblon, Spivak, McClelland, Maier & Neustadt, P.C.

Foreign Patent References

0 162 929 EP 12/12/1985
0 168 054 EP 01/12/1986
0 299 711 EP 01/12/1989
2 168 508 GB 06/12/1986
2 175 112 GB 11/12/1986

International Classes

H04L 009/00
H04L 009/28

Foreign Application Priority Data

1992-05-29 JP

Abstract

A block processing section divides message data into a plurality of blocks, so as to obtain a plurality of data blocks. A plurality of data encryption processing sections are provided in correspondence to the data blocks. The first one of the data encryption processing sections selects one of pre-stored data conversion algorithms in response to an initial selection control signal. Each of the remaining data encryption processing sections selects one of the data conversion algorithms in response to a selection control signal supplied from a preceding data encryption processing section. Each of the data encryption processing sections performs data encryption processing with respect to the corresponding data block on the basis of the selected data conversion algorithm, and generates a selection control signal to be supplied to the succeeding data encryption processing section, on the basis of the data obtained by the data encryption processing.