sLiSCP-light permutation More...

#include "internal-util.h"

Macros
#define	SLISCP_LIGHT256_STATE_SIZE 32
	Size of the state for sLiSCP-light-256.

#define	SLISCP_LIGHT192_STATE_SIZE 24
	Size of the state for sLiSCP-light-192.

#define	SLISCP_LIGHT320_STATE_SIZE 40
	Size of the state for sLiSCP-light-320.

Functions
void	sliscp_light256_permute_spix (unsigned char block[32], unsigned rounds)
	Performs the sLiSCP-light permutation on a 256-bit block. More...

void	sliscp_light256_swap_spix (unsigned char block[32])
	Swaps rate bytes in a sLiSCP-light 256-bit block for SPIX. More...

void	sliscp_light256_permute_spoc (unsigned char block[32])
	Performs the sLiSCP-light permutation on a 256-bit block. More...

void	sliscp_light256_swap_spoc (unsigned char block[32])
	Swaps rate bytes in a sLiSCP-light 256-bit block for SpoC-128. More...

void	sliscp_light192_permute (unsigned char block[24])
	Performs the sLiSCP-light permutation on a 192-bit block. More...

void	sliscp_light320_permute (unsigned char block[40])
	Performs the sLiSCP-light permutation on a 320-bit block. More...

void	sliscp_light320_swap (unsigned char block[40])
	Swaps rate bytes in a sLiSCP-light 320-bit block. More...

Detailed Description

sLiSCP-light permutation

There are three variants of sLiSCP-light in use in the NIST submissions:

sLiSCP-light-256 with a 256-bit block size, used in SPIX and SpoC.
sLiSCP-light-192 with a 192-bit block size, used in SpoC.
sLiSCP-light-320 with a 320-bit block size, used in ACE.

References: https://uwaterloo.ca/communications-security-lab/lwc/ace, https://uwaterloo.ca/communications-security-lab/lwc/spix, https://uwaterloo.ca/communications-security-lab/lwc/spoc

Function Documentation

void sliscp_light192_permute ( unsigned char block[24] )

Performs the sLiSCP-light permutation on a 192-bit block.

Parameters

block Points to the block to be permuted.

void sliscp_light256_permute_spix	(	unsigned char	block[32],
		unsigned	rounds
	)

Performs the sLiSCP-light permutation on a 256-bit block.

Parameters

block	Points to the block to be permuted.
rounds	Number of rounds to be performed, usually 9 or 18.

The bytes of the block are assumed to be rearranged to match the requirements of the SPIX cipher. SPIX places the rate bytes at positions 8, 9, 10, 11, 24, 25, 26, and 27.

This function assumes that bytes 24-27 have been pre-swapped with bytes 12-15 so that the rate portion of the state is contiguous.

The sliscp_light256_swap_spix() function can be used to switch between the canonical order and the pre-swapped order.

See Also: sliscp_light256_swap_spix()

void sliscp_light256_permute_spoc ( unsigned char block[32] )

Performs the sLiSCP-light permutation on a 256-bit block.

Parameters

block Points to the block to be permuted.

The bytes of the block are assumed to be rearranged to match the requirements of the SpoC-128 cipher. SpoC-128 interleaves the rate bytes and the mask bytes. This version assumes that the rate and mask are in contiguous bytes of the state.

SpoC-128 absorbs bytes using the mask bytes of the state at offsets 8, 9, 10, 11, 12, 13, 14, 15, 24, 25, 26, 27, 28, 29, 30, and 31. It squeezes bytes using the rate bytes of the state at offsets 0, 1, 2, 3, 4, 5, 6, 7, 16, 17, 18, 19, 20, 21, 22, and 23.

This function assumes that bytes 8-15 have been pre-swapped with 16-23 so that the rate and mask portions of the state are contiguous.

The sliscp_light256_swap_spoc() function can be used to switch between the canonical order and the pre-swapped order.

See Also: sliscp_light256_swap_spoc()

void sliscp_light256_swap_spix ( unsigned char block[32] )

Swaps rate bytes in a sLiSCP-light 256-bit block for SPIX.

Parameters

block Points to the block to be rate-swapped.

See Also: sliscp_light256_permute_spix()

void sliscp_light256_swap_spoc ( unsigned char block[32] )

Swaps rate bytes in a sLiSCP-light 256-bit block for SpoC-128.

Parameters

block Points to the block to be rate-swapped.

See Also: sliscp_light256_permute_spoc()

void sliscp_light320_permute ( unsigned char block[40] )

Performs the sLiSCP-light permutation on a 320-bit block.

Parameters

block Points to the block to be permuted.

The ACE specification refers to this permutation as "ACE" but that can be confused with the name of the AEAD mode so we call this permutation "sLiSCP-light-320" instead.

ACE absorbs and squeezes data at the rate bytes 0, 1, 2, 3, 16, 17, 18, 19. Efficiency can suffer because of the discontinuity in rate byte positions.

To counteract this, we assume that the input to the permutation has been pre-swapped: bytes 4, 5, 6, 7 are swapped with bytes 16, 17, 18, 19 so that the rate is contiguous at the start of the state.

The sliscp_light320_swap() function can be used to switch between the canonical order and the pre-swapped order.

See Also: sliscp_light320_swap()

void sliscp_light320_swap ( unsigned char block[40] )

Swaps rate bytes in a sLiSCP-light 320-bit block.

Parameters

block Points to the block to be rate-swapped.

See Also: sliscp_light320_permute()

Macros

Functions

Detailed Description

Function Documentation