OAEP-ES--Methodology of Universal Padding Technique--

Yuichi KOMANO  Kazuo OHTA 

Publication
IEICE TRANSACTIONS on Fundamentals of Electronics, Communications and Computer Sciences  Vol.E87-A  No.1  pp.110-119
Publication Date: 2004/01/01
Online ISSN: 
Print ISSN: 0916-8508
Type of Manuscript: Special Section PAPER (Special Section on Cryptography and Information Security)
Category: Asymmetric Cipher
Keyword: 
OAEP,  PSS,  universal padding,  reduction,  provably secure, 

Full Text: PDF(316.9KB)

Summary: 
The new concept of ES (Encryption-Signature) schemes which realize an encryption scheme and a signature scheme with a unique padding technique and key pair, was proposed by Coron et al. They also gave a proof of PSS-ES. In this paper, first, we discuss the methodology for the construction for ES schemes by using padding techniques of encryption schemes, and propose a new ES scheme, OAEP-ES, adopting this methodology. It is proven that OAEP-ES scheme can be constructed under the assumption of the one-wayness of the encryption permutation, while the security of PSS-ES utilized as an encryption scheme is based on the partial-domain one-wayness; which is a theoretical progress since the one-wayness is more general assumption than the partial-domain one-wayness. It is shown that OAEP-ES attains tighter security than PSS-ES, which is a practical interest.