Paper Info
Title
Partial Key Exposure Attacks on Unbalanced RSA with the CRT*This work was supported by Kangnam University Research Grant in 2005. This work was also supported in part by Grant R08-2003-000-11029-0 from the Basic Research Program of the Korea Research Foundation.
Abstract
In RSA public-key cryptosystem, a small private key is often preferred for efficiency but such a small key could degrade security. Thus the Chinese Remainder Theorem (CRT) is tactically used, especially in time-critical applications like smart cards. As for using the CRT in RSA, care must be taken to resist partial key exposure attacks. While it is common to choose two distinct primes with similar size in RSA, May has shown that a composite modulus N can be factored in the balanced RSA with the CRT of half of the least (or most) significant bits of a private key is revealed with a small public key. However, in the case that efficiency is more critical than security, such as smart cards, unbalanced primes might be chosen. Thus, we are interested in partial key exposure attacks to the unbalanced RSA with the CRT. In this paper, we obtain the similar results as the balanced RSA. We show that in the unbalanced RSA if the N1/4 least (or most) significant bits are revealed, a private key can be recovered in polynomial time under a small public key.
Year
DOI
Venue
2006
10.1093/ietfec/e89-a.2.626
IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences
Keywords
DocType
Volume
Partial Key Exposure Attacks,Basic Research Program,partial key exposure attack,private key,small public key,Korea Research Foundation,Kangnam University Research Grant,unbalanced RSA,smart card,RSA public-key cryptosystem,balanced RSA,small private key,small key,Unbalanced RSA,significant bit
Journal
E89-A
Issue
ISSN
Citations 
2
0916-8508
0
PageRank 
References 
Authors
0.34
0
3
Name
Order
Citations
PageRank
Hee Jung Lee171.67
Young-Ho Park213716.79
Taekyoung Kwon31894153.24