The ChaCha family of stream ciphers,
also known as Snuffle 2008,
is a variant of the
Salsa20 family of stream ciphers.
The following paper introduces ChaCha and compares it to Salsa20:
[chacha]
6pp.
(PDF)
D. J. Bernstein.
ChaCha, a variant of Salsa20.
Document ID: 4027b5256e17b9796842e6d0f68b0b5e.
URL: https://cr.yp.to/papers.html#chacha.
Date: 2008.01.28.
Supersedes:
(PDF)
2008.01.20.
The Salsa20 directory in version 2008.01.20 of the eSTREAM benchmarking suite
includes several implementations of ChaCha8 (and ChaCha12 and ChaCha20):
x86-mmx,
specific to the Pentium Pro and other CPUs with MMX registers:
chacha.q,
chacha.s,
Makefile,
ecrypt-sync.h.
Uses some MMX registers as substitutes for stack positions.
x86-xmm2,
specific to the Pentium 4 and other CPUs with SSE2 instructions:
chacha.q,
chacha.s,
Makefile,
ecrypt-sync.h.
Selects different SSE2 instructions.
x86-xmm5,
specific to the Pentium 4 and other CPUs with SSE2 instructions:
chacha.q,
chacha.s,
Makefile,
ecrypt-sync.h.
Handles four blocks in parallel.
Based on analogous Salsa20 code by Wei Dai.
amd64-xmm6,
specific to the Athlon 64, Core 2 Duo, and other AMD64 chips:
chacha.q,
chacha.s,
Makefile,
ecrypt-sync.h.
Translation of x86-xmm5, with some additional instruction scheduling.
ppc-altivec,
specific to the PowerPC G4 and other CPUs with AltiVec instructions:
chacha.c,
Makefile,
ecrypt-sync.h.
Based on analogous Salsa20 code by Matthijs van Duin.
