Abstract

Refemma cued A system and method for data escrow cryptography are described. An encrypting user encrypts a message using a
. S. PATENT DOCUMENTS U secret storage key (KS) and attaches a data recovery? eld 4,200,770 4/1980 Ct 21. 380/30 (DRF) including an access rulg indcx and KS ‘[0 [ha 4,336,233 5/1933 5|?“e ‘31 330'30 encrypted message. The DRF and the encrypted message are 4, 4053” 9/1933 Rm?‘at al' 330/30 stored in a storage device. To recover KS. a decrypting user foemg‘ extracts and sends the DRF to a data recovery center (DRC) 4’868’877 9/1989 13: 22::' 380, 25 that issues a challenge based on access rules (ARs) origi 4: 9Q6: 480 5/1990 Chum'380, 30 nally de? ned by the encrypting user. If the decrypting user 4,947,430 3/1990 (31mm 330/25 meets the challenge, the DRC sends KS in a message to the 4,996,711 2/1991 Chaum. 380/30 decrypting user. Generally. KS need not …

Date

1998

Authors

SB Lipner, DM Balenson, CM Ellison, ST Walker

Inventors

Steven B Lipner, David M Balenson, Carl M Ellison, Stephen T Walker

Patent_office

US

Patent_number

5745573

Application_number

08781626