Method and apparatus for encrypting/decrypting data
AssigneeHewlett-Packard Development Company, L.P.
InventorsMarco Casassa Mont, Keith Alexander Harrison, Martin Sadler
Life of this patent
Estimating the term…
Abstract
A computer system comprises a first computer entity arranged to encrypt data using an encryption key comprising a time value, and a second computer entity arranged to generate, at intervals, a decryption key using a current time value. The encryption and decryption processes are such that the decryption key generated using a current time value corresponding to that used for the encryption key, is apt to decrypt the encrypted s data.
Claims21
A security method, comprising:
- first operations, effected by a discloser of data, comprising encrypting the data and providing the encrypted data to a recipient, the encryption process using both an encryption key comprising a time value and public data provided by a trusted party and derived thereby from private data;
- and
- second operations, effected by the trusted party, comprising using both said private data and further data in order to determine, at intervals, a decryption key which is then output;
- said further data comprising, at each determination of the decryption key, a new current time value derived independently of said encryption key, the decryption key being so determined that, for a said current time value equalling the time value used by the data discloser for its encryption key, the decryption key is apt to decrypt the discloser's encrypted data.
A computer system comprising:
- a first computing entity arranged to encrypt, for output, first data according to an encryption process involving both an encryption key comprising a time value, and second data provided by a trusted party;
- a second computing entity associated with the trusted party and arranged to determine, for output, a decryption key using both third data and fourth, private, data from which said second data has been derived;
- the second computing entity being arranged to determine said decryption key at intervals using as said third data, at each determination, a new current time value derived independently of said encryption key, and
- a third computing entity arranged to receive both the encrypted first data and the decryption key, and to decrypt the received encrypted first data using the received decryption key determined using as said third data a said current time value equalling the time value used by the first computing entity for its encryption key.
Apparatus for generating a decryption key, comprising a memory for holding private data, a clock, and a processor for generating, at intervals, a decryption key using both said private data and a current time value from the clock, each decryption key generated being apt to decrypt data encrypted using both public data derived from said private data and a time value corresponding to the current time value used in generating the decryption key.
Dependencies are inferred from the claim text.