Patent ID: 8818019

Claim:
A method for embedding a watermark in block encrypted content, the method comprising: providing an MPEG packet, the MPEG packet comprising a payload; dividing the payload into N blocks of equal size, each block denoted as one of b 0 -b n-2 and b x ; determining b 0 ⊕ . . . ⊕b n-2 =B providing a byte, denoted A, in an MPEG header, A being an adaptation field comprising proprietary parameters; encrypting, according to an encryption function f, f(b x , B, A), where an encryption key for the encryption function f comprises g(A,B); selecting a value k, where 0<=k<32; and calculating Y=f(bx, B, A), Y being a 16 byte long vector; calculate P k (Y); determine if P k (Y)=the k th bit of the watermark; if P k (Y)=the k th bit of the watermark then continuing to a next MPEG packet; if P k (Y) does not equal the k th bit of the watermark, then increment A and repeat the above procedure until one of: P k (Y)=the k th bit of the watermark; and a predetermined upper bound is reached, in which case, the provided MPEG packet does not participate in the watermarking process.