The Theory of Hash Functions and Random Oracles

2021 ◽  
Author(s):  
Arno Mittelbach ◽  
Marc Fischlin
Keyword(s):  
Hash Functions ◽  
Random Oracles

scholarly journals On Pseudo-Random Oracles

2012 ◽  
Vol 53 (1) ◽  
pp. 155-187
Author(s):  
Michal Rjaško
Keyword(s):  
Hash Function ◽  
Random Function ◽  
Hash Functions ◽  
Random Oracle Model ◽  
Random Oracle ◽  
Public Image ◽  
Signature Schemes ◽  
Random Oracles ◽  
Random Behavior ◽  
Domain Extension

ABSTRACT Many cryptographic systems which involve hash functions have proof of their security in a so called random oracle model. Behavior of hash functions used in such cryptographic systems should be as close as possible to the behavior of a random function. There are several properties of hash functions dealing with a random behavior. A hash function is pseudo-random oracle if it is indifferentiable from a random oracle. However, it is well known that hash functions based on the popular Merkle-Damg˚ard domain extension transform do not satisfy the pseudo-random oracle property. On the other hand no attack is known for many concrete applications utilizing Merkle-Damg˚ard hash functions. Hence, a weakened notion called public-use pseudo random oracle was introduced. The property can be met by the Merkle-Damg˚ard construction and is sufficient for several important applications. A hash function is public use pseudo-random oracle if it is indifferentiable from a random oracle with public messages (i.e., all messages hashed so far are available to all parties). This is the case of most hash based signature schemes. In this paper we analyze relationship between the property pseudo-random oracle and its variant public image pseudo-random oracle. Roughly, a hash function is public image pseudo-random oracle if it is indifferentiable from a random oracle with public images (i.e., all images of messages hashed so far are available to all parties, messages are kept secret). We prove that the properties are equivalent.

A CCA2-Secure Multi-Decrypter Encryption Scheme Without Random Oracles

Informatica ◽  
2015 ◽  
Vol 26 (3) ◽  
pp. 543-556
Author(s):  
Shengbao Wang ◽  
Peng Zeng ◽  
Kim-Kwang Raymond Choo ◽  
Hongbing Wang
Keyword(s):  
Encryption Scheme ◽  
Random Oracles

Sender Authenticated Key Agreements without Random Oracles

2009 ◽  
Vol E92-A (8) ◽  
pp. 1787-1794
Author(s):  
Chifumi SATO ◽  
Takeshi OKAMOTO ◽  
Eiji OKAMOTO
Keyword(s):  
Random Oracles

Hash Functions Based on Block Ciphers

2009 ◽  
Vol 20 (3) ◽  
pp. 682-691
Author(s):  
Pin LIN ◽  
Wen-Ling WU ◽  
Chuan-Kun WU
Keyword(s):  
Hash Functions ◽  
Block Ciphers
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