Abstract:
In this work, we throw light on gaps between theoretical construction of cryptographic primitives
and their practical instantiation. It is assumed that cryptographic primitives will not have any
trapdoors in the given design. It is also assumed that security of a cryptographic construction
should remain the same in practice as proven in theory. We show how a designer can act as
adversary if he doesn't follow some basic paradigms while designing. To ensure that the basic
assumptions, made while providing security proof of cryptographic construction, remain true
and doubt free, we show that order of de ning the underlying primitives of security protocols
are important.
We use Hash-then-Truncate(HtT) construction as an example. While discussing security of HtT
construction we show that order of de ning hash and truncation function is important. We
also show that by providing choices of hash functions from a hash family to a user, we can
securely instantiate the HtT construction. In this way, we can bridge the gap between design
and practice.
