Hardware optimizations of stream cipher rabbit

Stream ciphers form part of cryptographic primitives focused on privacy. Synchronous, symmetric and software-oriented stream cipher Rabbit is member of final portfolio of European Union's eStream project. Although it was designed to perform well in software, employed operations seem to compute effi­ciently in hardware. 128-bit security, with no known security weaknesses is claimed by Rabbit's designers. Since hardware performance of Rabbit was only estimated in the proposal of algorithm, comparison of direct and optimized FPGA im­plementations of Rabbit stream cipher is presented, identifying algorithm bot­tlenecks, discussing optimization techniques applied to algorithm computations, along with key area/time trade-offs.