2020. 1. 27. 23:07ㆍ카테고리 없음
HMAC is the most widely-deployed cryptographic-hash-function-based message authentication code. First, we describe a security issue that arises because of inconsistencies in the standards and the published literature regarding keylength. We prove a separation result between two versions of HMAC, which we denote and, the former being the real-world version standardized by Bellare et al. in 1997 and the latter being the version described in Bellare's proof of security in his Crypto 2006 paper. Second, we describe how (the FIPS version standardized by NIST), while provably secure (in the single-user setting), succumbs to a practical attack in the multi-user setting. Third, we describe a fundamental defect from a practice-oriented standpoint in Bellare's 2006 security result for HMAC, and show that because of this defect his proof gives a security guarantee that is of little value in practice.
Doi 10.1515 Jmc- De Gruyter Indirect Banking
As well as indirect coupling mediated by radiative chan-nels. Indirect couplings in quasi-bound states have been widely studied in various open quantum systems, includ-ing nuclei, atoms, molecules, and quantum dots [26]. It has been shown that the indirect coupling gives rise to an imaginary or anti-Hermitian coupling matrix in the system. Indirect message injection for MACs 5 2.2 Structure of integrity algorithm For MAC generation using indirect message injection, the major components used are two registers, each consisting of dbinary stages, where dis the length of the MAC tag. The relationship between these two.
Doi 10.1515 Jmc- De Gruyter Indirect L
We give a new proof of NMAC security that gives a stronger result for NMAC and HMAC and we discuss why even this stronger result by itself fails to give convincing assurance of HMAC security.