Showing papers on "Plaintext-aware encryption published in 1995"
27 Aug 1995
TL;DR: This paper demonstrates that the RSA based scheme is insecure under an adaptive chosen ciphertext attack, and point weaknesses in the design of both their RSA and EI Gamal based schemes regarding the use of pseudorandom-generators.
Abstract: In CRYPTO '93 Lim and Lee provided a valuable investigation of public key encryption systems secure against adaptive chosen ciphertext attacks. In this paper we identify several insecurities of both their RSA and El Gamal based schemes. We first demonstrate that the RSA based scheme is insecure under an adaptive chosen ciphertext attack. We also point weaknesses in the design of both their RSA and EI Gamal based schemes regarding the use of pseudorandom-generators, and in particular show that their choice of pseudorandom-generators for the RSA based scheme may be insecure even with respect to a known ciphertext only attack.They further claim that their schemes are particularly useful in the context of group-oriented cryptosystems due to the unique verification method used. (In fact their scheme is the only group-oriented practical encryption claimed to be secure against chosen ciphertext attacks). Group oriented cryptosystems distribute the decryption process amongst a multiple of individuals in order to provide a mechanism in which no single person is trusted. We further demonstrate that both their schemes are completely insecure in this setting.
18 citations
TL;DR: A two-phase encryption algorithm for data base systems that allows the encryption and decryption of fields within a record by means of writing and reading subkeys of fields and two algorithms for cryptographic relational algebra in data base system are developed.
18 citations
24 Aug 1995
TL;DR: In this article, the authors proposed an approach toward public-key cryptosystems based on finite string rewriting systems with Church-Rosser property, which utilizes an existence of unique normal form for any congruence class modulo such a system and possibility to find it in linear time.
Abstract: We propose an approach toward public-key cryptosystems based on finite string-rewriting systems with Church-Rosser property The approach utilizes an existence of unique normal form for any congruence class modulo such a system and possibility to find it in linear time Such cryptosystems can be used in the case we are dealing with a large network of communicating parties when it is impractical to use a distinct secret method signing for every pair users and we would like to have a unified secret method for all senders sending to a receiver
7 citations
Patent•
NEC1
TL;DR: In this paper, a quadratic residue calculation circuit calculates a residue when the square of the lower n-1 bits of the plaintext of n bits is divided by public-key.
Abstract: The invention provides a public-key cryptographic apparatus which does not leak information regarding a plaintext and can prevent an increase in block length. A quadratic residue calculation circuit calculates a residue when the square of the lower n-1 bits of the plaintext of n bits is divided by public-key, and an exclusive OR circuit calculates an exclusive OR of the least significant bit of a result of the calculation and the most significant bit of the plaintext. Then, public-key encipherment such as the RSA cryptosystem or a modified Rabin cryptosystem is performed twice repetitively for totaling n bits of the output of exclusive OR circuit and the lower n-1 bits of plaintext by public-key enciphering circuits so as to make it impossible to estimate the most significant bit of the plaintext from the ciphertext.
5 citations