Method and apparatus for tracing the source of decryption keys used by a decoder

US7970141B2 · kind B2 · utility

Assignees

• The Regents of the University of California · US
• SRI International · US
• The Board of Trustees of the Leland Stanford Junior University · US

Inventors

• Dan Boneh · Palo Alto, US
• Amit Sahai · Cambridge, US
• Brent Waters · Austin, US

Key dates

• Filing date: Sep 13, 2007
• Grant date: Jun 28, 2011
• Expiry date: Apr 6, 2030

Classification

• Technology area (CPC H): Electricity
• CPC primary: H04L2209/606
• WIPO field: Control
• WIPO sector: Instruments

Abstract

The present invention relates to a method for traitor tracing. One embodiment of a method for determining at least one traced private key used by a decoder to decrypt an encrypted message includes defining an input ciphertext, the input ciphertext being associated with a tracing private key and having a sublinear size, calling the decoder on the input ciphertext, and associating the tracing private key with a set of traced private keys if the decoder is able to correctly decrypt the encrypted message in accordance with the input ciphertext, the set of traced private keys including at least one private key.