fss::prp::ChaChaFeistel Class Reference

Small-domain ChaCha20-Feistel PRP for Cuckoo hashing. More...

Public Member Functions
__uint128_t	Permu (int4 seed, __uint128_t x, __uint128_t domain)
	Small-domain PRP on [0, domain) using 4-round Feistel + cycle-walking.

Detailed Description

Small-domain ChaCha20-Feistel PRP for Cuckoo hashing.

This backend satisfies Permutable, is usable from both host and device, and is intended for DMPF/VDMPF paths that need a permutation over a compact integer domain.

Member Function Documentation

Permu()

__uint128_t fss::prp::ChaChaFeistel::Permu ( int4 seed, __uint128_t x, __uint128_t domain )

inline

Small-domain PRP on [0, domain) using 4-round Feistel + cycle-walking.

Parameters

seed	16-byte PRP key.
x	Input in [0, domain).
domain	Domain size. Must be >= 2.

Returns

Output in [0, domain).

Precondition

x < domain. A violation aborts with a diagnostic in Debug builds on both the host and the device, and is undefined behavior in Release builds.

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The documentation for this class was generated from the following file:

• include/fss/prp/chacha_feistel.cuh