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This paper presents a secure (tamper-resistant) algorithm for watermarking images, and a methodology for digital watermarking that may be generalized to audio, video, and multimedia data. We advocate that a watermark should be constructed as an independent and identically distributed (i.i.d.) Gaussian random vector that is imperceptibly inserted in a(More)
Let F be some block cipher (eg., DES) with block length l. The Cipher Block Chaining Message Authentication Code (CBC MAC) speci es that an m-block message x = x1 xm be authenticated among parties who share a secret key a for the block cipher by tagging x with a pre x of ym, where y0 = 0 l and yi = Fa(mi yi 1) for i = 1; 2; : : : ;m. This method is a(More)
Suppose your netmail is being erratically censored by Captain Yossarian. Whenever you send a message, he censors each bit of the message with probability 1/2, replacing each censored bit by some reserved character. Well versed in such concepts as redundancy, this is no real problem to you. The question is, can it actually be turned around and used to your(More)
Quite complex cryptographic machinery has been developed based on the assumption that one-way functions exist, yet we know of only a few possible such candidates. It is important at this time to find alternative foundations to the design of secure cryptography. We introduce a new model of generalized interactive proofs as a step in this direction. We prove(More)
We consider the problem of extending oblivious transfers: Given a small number of oblivious transfers “for free,” can one implement a large number of oblivious transfers? Beaver has shown how to extend oblivious transfers given a one-way function. However, this protocol is inefficient in practice, in part due to its non-black-box use of the underlying(More)
The Cipher Block Chaining { Message Authentication Code (CBC MAC) speciies that a message x = x 1 x m be authenticated among parties who share a secret key a by tagging x with a preex of f (m) a (x) def = f a (f a (f a (f a (x 1)x 2) x m?1)x m) ; where f is some underlying block cipher (eg. f = DES). This method is a pervasively used international and U.S.(More)
We introduce the <i>Bloomier filter</i>, a data structure for compactly encoding a function with static support in order to support approximate evaluation queries. Our construction generalizes the classical Bloom filter, an ingenious hashing scheme heavily used in networks and databases, whose main attribute---space efficiency---is achieved at the expense(More)
We describe a digital watermarking method for use in audio, image, video and multimedia data. We argue that a watermark must be placed in perceptually significant components of a signal if it is to be robust to common signal distortions and malicious attack. However, it is well known that modification of these components can lead to perceptual degradation(More)