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Encryption method, encryption apparatus, recording method, decoding method, decoding apparatus and recording medium

  • US 5,796,839 A
  • Filed: 10/15/1996
  • Issued: 08/18/1998
  • Est. Priority Date: 10/16/1995
  • Status: Expired due to Fees
First Claim
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1. A method of encrypting predetermined information by using a predetermined encryption key comprising the steps of:

  • hierarchizing the encryption of said encryption key by sequentially encrypting a version of an encryption key from an immediate previously encrypted version of an encryption key by using a one way function, anddecoding said predetermined information by using said hierarchized encryption of said encryption key wherein only a subsequent version excluding a first master version of an encryption key is able to decode the predetermined information of a previous version of an encryption key.

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