3 Ja n 20 08 Merkle Puzzles are Optimal

Merkle Puzzles Are Optimal - An O(n2)-Query Attack on Any Key Exchange from a Random Oracle

We prove that every key exchange protocol in the random oracle model in which the honest users make at most n queries to the oracle can be broken by an adversary making O(n) queries to the oracle. This improves on the previous Ω̃(n) query attack given by Impagliazzo and Rudich (STOC ’89), and answers an open question posed by them. Our bound is optimal up to a constant factor since Merkle (CACM ...

Merkle Puzzles are Optimal

We prove that every key exchange protocol in the random oracle model in which the honest users make at most n queries to the oracle can be broken by an adversary making O(n) queries to the oracle. This improves on the previous Ω̃(n) query attack given by Impagliazzo and Rudich (STOC ’89). Our bound is optimal up to a constant factor since Merkle (CACM ’78) gave an n query key exchange protocol i...

Merkle Puzzles are Optimal — an O(n)-query attack on key exchange from a random oracle

We prove that every key exchange protocol in the random oracle model in which the honest users make at most n queries to the oracle can be broken by an adversary making O(n) queries to the oracle. This improves on the previous Ω̃(n) query attack given by Impagliazzo and Rudich (STOC ’89). Our bound is optimal up to a constant factor since Merkle (CACM ’78) gave an n query key exchange protocol i...

Optimal trade-off for merkle tree traversal

In this paper we describe optimal trade-offs between time and space complexity of Merkle tree traversals with their associated authentication paths, improving on the previous results of M. Jakobsson, T. Leighton, S. Micali, and M. Szydlo [Fractal Merkle tree representation and traversal, in: RSA Cryptographers Track, RSA Security Conference, 2003] and M. Szydlo [Merkle tree traversal in log spa...

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