NAME

Math::Prime::Util::ChaCha - Pure Perl ChaCha20 CSPRNG

VERSION

Version 0.73

SYNOPSIS

DESCRIPTION

A pure Perl implementation of ChaCha20 with a CSPRNG interface.

FUNCTIONS

csrand

Takes a binary string as input and seeds the internal CSPRNG.

srand

A method for sieving the CSPRNG with a small value. This will not be secure but can be useful for simulations and emulating the system "srand".

With no argument, chooses a random number, seeds and returns the number. With a single integer argument, seeds and returns the number.

irand

Returns a random 32-bit integer.

irand64

Returns a random 64-bit integer.

random_bytes

Takes an unsigned number "n" as input and returns that many random bytes as a single binary string.

AUTHORS

Dana Jacobsen <dana@acm.org>

ACKNOWLEDGEMENTS

Daniel J. Bernstein wrote the ChaCha family of stream ciphers in 2008 as an update to the popular Salsa20 cipher from 2005.

RFC7539: "ChaCha20 and Poly1305 for IETF Protocols" was used to create both the C and Perl implementations. Test vectors from that document are used here as well.

For final optimizations I got ideas from Christopher Madsen's Crypt::Salsa20 for how to best work around some of Perl's aggressive dynamic typing. Our core is still about 20% slower than Salsa20.

COPYRIGHT

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.