Title
Cryptanalysis of RSA Using the Ratio of the Primes
Abstract
Let N = pq be an RSA modulus, i.e. the product of two large unknown primes of equal bit-size. In the X 9.31-1997 standard for public key cryptography, Section 4.1.2, there are a number of recommendations for the generation of the primes of an RSA modulus. Among them, the ratio of the primes shall not be close to the ratio of small integers. In this paper, we show that if the public exponent e satisfies an equation eX *** (N *** (ap + bq ))Y = Z with suitably small integers X , Y , Z , where $\frac{a}{b}$ is an unknown convergent of the continued fraction expansion of $\frac{q}{p}$, then N can be factored efficiently. In addition, we show that the number of such exponents is at least $N^{\frac{3}{4}-\varepsilon}$ where *** is arbitrarily small for large N .
Year
DOI
Venue
2009
10.1007/978-3-642-02384-2_7
AFRICACRYPT
Keywords
Field
DocType
continued fraction expansion,unknown convergent,equal bit-size,large unknown prime,public key cryptography,large n,suitably small integers x,public exponent e,rsa modulus,small integer,satisfiability,continued fraction,factorization,cryptanalysis
Integer,Discrete mathematics,Continued fraction,Exponent,Cryptanalysis,Factorization,Public-key cryptography,Mathematics
Conference
Volume
ISSN
Citations 
5580
0302-9743
1
PageRank 
References 
Authors
0.36
9
1
Name
Order
Citations
PageRank
Abderrahmane Nitaj17215.00