Encrypting data for access by multiple users

Details Encrypting data for access by multiple users Encrypting data for access by multiple users

2007-09-18

2007-09-18

Jung, David Y. (Department: 2134)

Cryptography

Key management

Key distribution

C380S285000, C380S259000, C713S165000, C713S183000, C713S184000, C713S189000

Reexamination Certificate

active

10351759

ABSTRACT:
A method for protecting data for access by a plurality of users. A server encrypts data using a master key and a symmetric encryption algorithm. For each authorized user, a key encryption key (KEK) is derived from a passphrase, and the master key is encrypted using the KEK. The server posts the encrypted data and an ancillary file that includes, for each user, a user identifier and the master key encrypted according to the user's KEK. To access the data, a user enters the passphrase into a client, which re-derives the user's KEK, and finds, in the ancillary file, the master key encrypted using the user's KEK. The client decrypts the master key and then decrypts the data. A KEK may be derived from a natural language passphrase by hashing the passphrase, concatenating the result and a predetermined text, hashing the concatenation, and truncating.

REFERENCES:
patent: 5495533 (1996-02-01), Linehan et al.
patent: 6016491 (2000-01-01), Kou
patent: 6018583 (2000-01-01), Hawthorne
patent: 6044405 (2000-03-01), Driscoll, III et al.
patent: 6157722 (2000-12-01), Lerner et al.
patent: 6185685 (2001-02-01), Morgan et al.
patent: 6199162 (2001-03-01), Luyster
patent: 6215878 (2001-04-01), Harkins
patent: 6249866 (2001-06-01), Brundrett et al.
patent: 6339828 (2002-01-01), Grawrock et al.
patent: 6694025 (2004-02-01), Epstein et al.
patent: 6819766 (2004-11-01), Weidong
patent: 6834112 (2004-12-01), Brickell
patent: 6959086 (2005-10-01), Ober et al.
patent: 7065214 (2006-06-01), Ishiguro et al.
patent: 2002/0071564 (2002-06-01), Kurn et al.
patent: 2002/0099666 (2002-07-01), Dryer et al.
patent: 2003/0074566 (2003-04-01), Hypponen
patent: 2003/0204732 (2003-10-01), Audebert et al.
patent: WO0013162 (2000-03-01), None
patent: WO0198873 (2001-12-01), None
Ragab, A. et al. “An Efficient Message Digest Algorithm (MD) For Data Security”, IEEE Catalogue No. 01CH37239, pp. 191-197, 2001.
Douceur, J. et al. “Reclaiming Space From Duplicate Files in a Serverless Distributed System”, IEEE 1063-6927.02, 2002.
Jiang, J. “Pipeline Algorithms of RSA Data Encryption and Data Compression” IEEE 0-7803-2916-3, pp. 1088-1091, 1994.
PGP Web Site at MIT “Cryptography”, Jan. 2003 http://www.trincoll.edu/depts/cpsc/cryptography/pgp.html.
Reeds, J. et al. “File Security and the UNIX System Crypt Command”, AT&T Bell Laboratories Technical Journal, vol. 63, No. 8, pp. 1673-1683, Oct. 1984.
Wong, K. W. “A Fast Chaotic Cryptographic Scheme with Dynamic Look-Up Table”, Physics Letters, Part A, vol. 298, No. 4, pp. 238-242, Jun. 10, 2002.

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