Paper 2024/103

ChaCha related 64 bit oriented ARX cipher

Daniel Nager
Abstract

A cipher scheme related to ChaCha [Ber] with the variation of using 64 bit operations instead of 32 bits, and the same 512 bit state size, is presented. We will provide strong argumentation to assert that the same security of ChaCha can be obtained with less number of instructions for 24 rounds, instead of Chacha's 20 rounds. Also, an strategy to implement this cipher on SIMD extensions is presented, with a maximal throughput of about 4 bytes per cycle on a 256 bit SIMD extension with at least 11 vector registers.

Metadata
Available format(s)
PDF
Category
Secret-key cryptography
Publication info
Preprint.
Keywords
ChachaARX64 bit
Contact author(s)
daniel nager @ gmail com
History
2024-02-06: revised
2024-01-23: received
See all versions
Short URL
https://ia.cr/2024/103
License
No rights reserved
CC0

BibTeX

@misc{cryptoeprint:2024/103,
      author = {Daniel Nager},
      title = {{ChaCha} related 64 bit oriented {ARX} cipher},
      howpublished = {Cryptology {ePrint} Archive, Paper 2024/103},
      year = {2024},
      url = {https://eprint.iacr.org/2024/103}
}
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