The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 03, 1991
Filed:
Jun. 29, 1990
William R Hawe, Pepperell, MA (US);
Joseph J Tardo, Acton, MA (US);
Charles W Kaufman, Northboro, MA (US);
Amar Gupta, Northboro, MA (US);
Barry A Spinney, Wayland, MA (US);
Gregory M Waters, Boston, MA (US);
Digital Equipment Corporation, Maynard, MA (US);
Abstract
A method and related cryptographic processing apparatus for handling information packets that are to be cryptographically processed prior to transmission onto a communication network, or that are to be locally cryptographically processed and looped back to a node processor. A special cryptographic preamble is included in each information packet that is to be subject to cryptographic processing. The cryptographic preamble contains an offset value pointing to the starting location of information that is to be processed, and completely defines the type of cryptographic processing to be performed. The cryptographic processor can then perform the processing as specified in the preamble without regard to a specific protocol. If the packet is to be transmitted onto the network, the preamble is stripped from the packet after cryptographic processing, so that the formats of packets transmitted onto the network will be unaffected by the preamble. Cryptographic processing modes include encryption of data for outbound transmission, encryption of a cipher key for loopback to the node processor, encryption or decryption of data for loopback to the node processor, and computation of an integrity check value for loopback to the node processor.