We present three security claims for iterated MAC functions. Next, we propose Alred, a construction method for MAC functions based on a block cipher that has provable security in the absence of internal collisions. We apply this construction to AES resulting in two MAC functions: Alpha-MAC and Pelican. We provide a model for describing different types of internal collisions in Alred and provide...

In this paper we introduce a classification of existing approaches to increase the security of block cipher operation modes based on re-keying, putting the focus on so-called internal re-keying without master key — re-keying during each separate message processing with no additional keys required. For extending the GCM base mode we provide an internal re-keying technique called ACPKM. This tech...

The importance of Business Process Modeling (BPM) particularly in sensitive areas combined with the rising impact of legislative requirements on IT operations results in a need to conceptually represent security semantics in BPM. We define critical security semantics that need to be incorporated in BPM to aid documentation of security needs and support compliant behavior of security systems. We...

This paper presents an eecient stream cipher using an internal state with variable structure and evolution. Arbitrarily large internal states can be used in order to defeat brute-force guessing attacks without compromising the performance of cipher, and possibly improving it. Attacking is made even more complicated by dynamically chosing diierent topologies and evo-lutions for the cipher's inte...