We present a formal view of cryptography that overcomes the usual assumptions of formal models for reasoning about security of computer systems, i.e. perfect cryptography and Dolev-Yao adversary model. In our framework, equivalence among formal cryptographic expressions is parameterized by a computational adversary that may exploit weaknesses of the cryptosystem to cryptanalyze ciphertext with a certain probability of success. To validate our approach, we show that in the restricted setting of ideal cryptosystems, for which the probability of guessing information that the Dolev-Yao adversary cannot derive is negligible, the computational adversary is limited to the allowed behaviors of the Dolev-Yao adversary.
Approximating Imperfect Cryptography in a Formal Model / Troina, Angelo; Aldini, Alessandro; Gorrieri, Roberto. - In: ELECTRONIC NOTES IN THEORETICAL COMPUTER SCIENCE. - ISSN 1571-0661. - ELETTRONICO. - 99:(2004), pp. 183-203. [10.1016/j.entcs.2004.02.008]
Approximating Imperfect Cryptography in a Formal Model
TROINA, ANGELO;GORRIERI, ROBERTO
2004
Abstract
We present a formal view of cryptography that overcomes the usual assumptions of formal models for reasoning about security of computer systems, i.e. perfect cryptography and Dolev-Yao adversary model. In our framework, equivalence among formal cryptographic expressions is parameterized by a computational adversary that may exploit weaknesses of the cryptosystem to cryptanalyze ciphertext with a certain probability of success. To validate our approach, we show that in the restricted setting of ideal cryptosystems, for which the probability of guessing information that the Dolev-Yao adversary cannot derive is negligible, the computational adversary is limited to the allowed behaviors of the Dolev-Yao adversary.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.