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Secure management of keys using extended control vectors

  • US 4,924,515 A
  • Filed: 08/24/1989
  • Issued: 05/08/1990
  • Est. Priority Date: 08/29/1988
  • Status: Expired due to Fees
First Claim
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1. In a data processing system which outputs cryptographic service requests for operations with cryptographic keys which are associated with control vectors defining the functions which each key is allowed by its originator to perform, an improved apparatus to enable the use of control vectors having a given length, comprising:

  • a control vector input for receiving a control vector of a given length associated with an N-bit cryptographic key;

    a control vector checking means having an input coupled to said control vector input and input for receiving a cryptographic service request, for checking that said control vector authorizes the cryptographic function which is requested by said cryptographic service request, and outputting an enable signal;

    a hash function generator having an input coupled to said control vector input and an N-bit output, for mapping said control vector into an N-bit hash value;

    a key input for receiving said N-bit cryptographic key;

    a logic block having a first input coupled to said N-bit output of said hash function generator, and a second input coupled to said key input, for forming at the output thereof a computed key value which is a product of said N-bit key and said N-bit hash value;

    a cryptographic transformation device having a first input for receiving input information and a key value input coupled to the output of said logic block, for forming output information which has been cryptographically transformed from said input information using said computed key value;

    said cryptographic transformation device coupled to said enable signal output from said control vector checking means for inhibiting said formation of said cryptographically transformed output information if said control vector checking means determines that said requested cryptographic function is not authorized by said control vector.

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