[HGI-News] HGI-Seminar, Montag 11.06.2007: Efficient Implementation of Stream Ciphers on Embedded Processors

[Newsletter des Horst Görtz Instituts]

               Gordon Meiser, Ruhr Universität Bochum

            Montag 11. Juni 2007, 13:15 Uhr IC 4 / 39-41

 Efficient Implementation of Stream Ciphers on Embedded Processors

This work is motivated by the question of how efficient modern stream
ciphers in the focus of eSTREAM Profile I (Phase 2) can be implemented
on small embedded microcontrollers. In response to this question, we
present the first implementation results for Dragon, HC-128, LEX, Salsa20
and Sosemanuk on 8-bit microcontrollers. For the evaluation process, we
follow a two-stage approach and compare with efficient AES implementations.
First, the C code implementation provided by the designers was ported to
an 8-bit AVR microcontroller and the suitability of Dragon, HC-128, LEX,
Salsa20 and Sosemanuk for the use in embedded systems was assessed. In
the second stage we implemented Dragon, LEX, Salsa20 and Sosemanuk in
Assembly to tap the full potential of an embedded implementation. Our
efficiency metrics are performance of keystream generation, key setup,
and IV setup, and memory usage in flash and SRAM, since microcontrollers
are usually strongly constrained in memory resources. Regarding encryption
speed, all stream ciphers turned out to outperform AES. In terms of memory
needs, Salsa20 and LEX are almost as compact as AES. When considering a
time-memory tradeoff metric, LEX and Salsa20 yield significantly better
results than AES.

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-- 
Für das HGI, Michael Psarros <michael.psarros at nds.rub.de>