Watermark With Data Integrity Verification

摘要

In one embodiment, a system including a processor is operative to receive a content item including a watermark encoding a series of encrypted bits deriving from encrypting an information element multiple times, extract at least some encrypted bits from at least part of the watermark, decrypt a series of N bits using a first key yielding a first value, the series of N bits including Q bits of the encrypted bits and K, greater than, or equal to zero, guessed bits, re-encrypt the first value using a second key yielding a second value, and compare at least part of the second value to M bits of the encrypted bits to determine if at least part of the second value matches the M bits in order to provide a level of confidence that the first value is the information element which was encrypted and embedded as the watermark.

主权项

1. A system comprising: a processor; and a memory to store data used by the processor, wherein the processor is operative to:
receive a media content item including a watermark embedded in the media content item, the watermark encoding a series of encrypted bits deriving from encrypting an information element multiple times with a plurality of cryptographic keys such that each of the times the encryption of the information element uses a different one of the cryptographic keys yielding a plurality of encrypted instances of the information element in the series of encrypted bits, the order of the cryptographic keys used in the series of encrypted bits being defined such that an ith encrypted instance of the information element in the series of encrypted bits being encrypted with an ith one of the cryptographic keys Ki, the information element consisting of N bits; identify at least part of the watermark in the media content item; extract at least some of the encrypted bits from the at least part of the identified watermark; decrypt a series of N bits using a first one of the cryptographic keys yielding a first value, the series of N bits including Q bits of the encrypted bits as ordered in the series of the encrypted bits and K guessed bits, K being greater than, or equal to, zero, K plus Q equaling N; re-encrypt the first value using a second one of the cryptographic keys yielding a second value, the second cryptographic key being different from the first cryptographic key; and compare at least part of the second value to M bits of the encrypted bits as ordered in the series of the encrypted bits to determine if the at least part of the second value matches the M bits as ordered in the series of the encrypted bits in order to provide a level of confidence that the first value is indeed the information element which was encrypted and embedded as the watermark in the media content item, the Q bits and the M bits being selected from different bits of the encrypted bits, M being greater than zero.