Title
Reducing Public Key Sizes In Bounded Cca-Secure Kems With Optimal Ciphertext Length
Abstract
Currently, chosen-ciphertext (CCA) security is considered as the de facto standard security notion for public key encryption (PKE), and a number of CCA-secure schemes have been proposed thus far. However, CCA-secure PKE schemes are generally less efficient than schemes with weaker security, e.g., chosen-plaintext security, due to their strong security. Surprisingly, Cramer et al. (Asiacrypt 2007) demonstrated that it is possible to construct a PKE scheme from the decisional Diffie-Hellman assumption that yields (i) bounded CCA (BCCA) security which is only slightly weaker than CCA security, and (ii) one group element of ciphertext overhead which is optimal.In this paper, we propose two novel BCCA-secure PKE schemes with optimal ciphertext length that are based on computational assumptions rather than decisional assumptions and that yield shorter (or at least comparable) public key sizes. Our first scheme is based on the computational bilinear Diffie-Hellman assumption and yields O(lambda q) group elements of public key length, and our second scheme is based on the factoring assumption and yields O(lambda q(2)) group elements of public key length, while in Cramer et al.' s scheme, a public key consists of O(lambda q(2)) group elements, where lambda is the security parameter and q is the number of decryption queries. Moreover, our second scheme is the first PKE scheme which is BCCA-secure under the factoring assumption and yields optimal ciphertext overhead.
Year
DOI
Venue
2013
10.1007/978-3-319-27659-5_7
INFORMATION SECURITY (ISC 2013)
Keywords
Field
DocType
Bounded CCA security, Factoring, CBDH assumption
De facto standard,Computer science,Theoretical computer science,Ciphertext,Security parameter,Public-key cryptography,Factoring,Bilinear interpolation,Bounded function,Lambda
Conference
Volume
ISSN
Citations 
7807
0302-9743
0
PageRank 
References 
Authors
0.34
9
5
Name
Order
Citations
PageRank
Takashi Yamakawa1129.35
Shota Yamada 00012513.05
Takahiro Matsuda 00023154.56
Goichiro Hanaoka4910101.53
Noboru Kunihiro542545.72