Adapting the Weaknesses of the Random Oracle Model to the Generic Group Model
نویسنده
چکیده
This paper presents results that show that there exist problems in that are provably hard in the generic group model but easy to solve whenever the random encoding function is replaced with a specific encoding function (or one drawn from a specific set of encoding functions). We also show that there exist cryptographic schemes that are provably hard in the generic group model but easy to break in practice.
منابع مشابه
A traceable optimistic fair exchange protocol in the standard model
An Optimistic Fair Exchange (OFE) protocol is a good way for two parties to exchange their digital items in a fair way such that at the end of the protocol execution, both of them receive their items or none of them receive anything. In an OFE protocol there is a semi-trusted third party, named arbitrator, which involves in the protocol if it is necessary. But there is a security problem when a...
متن کاملThe random oracle model: a twenty-year retrospective
It has been roughly two decades since the random oracle model for security reductions was introduced and one decade since we first discussed the controversy that had arisen concerning its use. In this retrospective we argue that there is no evidence that the need for the random oracle assumption in a proof indicates the presence of a realworld security weakness in the corresponding protocol. We...
متن کاملProvably secure and efficient identity-based key agreement protocol for independent PKGs using ECC
Key agreement protocols are essential for secure communications in open and distributed environments. Recently, identity-based key agreement protocols have been increasingly researched because of the simplicity of public key management. The basic idea behind an identity-based cryptosystem is that a public key is the identity (an arbitrary string) of a user, and the corresponding private key is ...
متن کاملSecurity of Discrete Log Cryptosystems in theRandom Oracle + Generic ModelClaus
Based on a novel proof model we prove security for simple discrete log cryptosystems for which security has been an open problem. We consider a combination of the random oracle (RO) model and the generic model. This corresponds to assuming an ideal hash function H given by an oracle and an ideal group of prime order q, where the binary encoding of the group elements is useless for cryptographic...
متن کاملAnother look at generic groups
Starting with Shoup’s seminal paper [24], the generic group model has been an important tool in reductionist security arguments. After an informal explanation of this model and Shoup’s theorem, we discuss the danger of flaws in proofs. We next describe an ontological difference between the generic group assumption and the random oracle model for hash functions. We then examine some criticisms t...
متن کامل