The utilization of hash functions and Keyed-Hash Message Authentication Codes (HMAC) are of utmost importance to ensure data integrity and data origin authentication in digital communications. Until recently, protocols used in the Internet, such as the Internet Key Exchange (IKE), Internet Protocol Security (IPSec) and Transport Layer Security (TLS), employed HMAC in conjunction with MD5 and SH...

In this paper, we present new security proofs of well-known hash constructions NMAC/HMAC proposed by Bellare et al. in 1996. We show that block ciphers should be used in hash functions in another way than it has been so far. We introduce a new cryptographic primitive called special block cipher (SBC) which is resistant to attacks specific for block ciphers used in hash functions. We propose to ...

Bellare, Canetti and Krawczyk [BCK96] show that cascading an ε-secure (fixed input length) PRF gives an O(εnq)-secure (variable input length) PRF when making at most q prefix-free queries of length n blocks. We observe that this translates to the same bound for NMAC (which is the cascade without the prefix-free requirement but an additional application of the PRF at the end), and give a matchin...

Modalclust is an R package which performs Hierarchical Mode Association Clustering (HMAC) along with its parallel implementation (PHMAC) over several processors. Modal clustering techniques are especially designed to efficiently extract clusters in high dimensions with arbitrary density shapes. Further, clustering is performed over several resolutions and the results are summarized as a hierarc...

The aim of this study is to make sure that the requested confidential digital object is authenticated and hence no tampering can be performed upon it particularly at the client-side. Thus a novel web client authentication system using smart card has been developed, called Dynamic HMAC Validation System (DHVS). The DHVS is based on HMAC technology where the ciphering key is dynamically generated...

In this paper, first we point out some flaws in the existing indifferentiability simulations of the pf-MD and the NMAC constructions, and provide new differentiable attacks on the hash functions based these schemes. Afterthat, the indifferentiability of the 20 collision resistant PGV hash functions, which are padded under the pf-MD, the NMAC/HMAC and the chop-MD constructions, are reconsidered....

In recent years, it has been proposed security architecture for sensor network.[2][4]. One of these, TinySec by Chris Kalof, Naveen Sastry, David Wagner had proposed Link layer security architecture, considering some problems of sensor network. (i.e : energy, bandwidth, computation capability,etc). The TinySec employs CBC_mode of encryption and CBC-MAC for authentication based on SkipJack Block...