Entity: keccak_2share

• File: keccak_2share.sv

Diagram

Description

Generics

Generic name	Type	Value	Description
Width	int	1600	b= {25, 50, 100, 200, 400, 800, 1600}
W	int	Width/25	Derived
L	int	$clog2(W)
MaxRound	int	12 + 2*L	Keccak-f only
RndW	int	$clog2(MaxRound+1)	Representing up to MaxRound
EnMasking	bit	0	Enable secure hardening
Share	int	EnMasking ? 2 : 1
ThetaIndexX1	int	undefined	(x-1)%5
ThetaIndexX2	int	undefined	(x+1)%5
ChiIndexX1	int	undefined	(x+1)%5
ChiIndexX2	int	undefined	(x+2)%5

Ports

Port name	Direction	Type	Description
clk_i	input
rst_ni	input
rnd_i	input	[RndW-1:0]	Current Round
rand_valid_i	input
rand_i	input	[Width-1:0]	Random values. Used when 2Share enabled
sel_i	input		Select input/output mux. Used when EnMasking := 1
s_i	input	[Width-1:0]
s_o	output	[Width-1:0]

Signals

Name	Type	Description
state_in	box_t	//////////// Keccak_f // ////////////
state_out	box_t
theta_data	box_t
rho_data	box_t
pi_data	box_t
chi_data	box_t
iota_data	box_t
phase1_in	box_t
phase1_out	box_t
phase2_in	box_t
phase2_out	box_t
result	box_t
result	return
iota	endfunction

Constants

Name	Type	Value	Description
W	int	Width/25	Derived
L	int	$clog2(W)
MaxRound	int	12 + 2*L	Keccak-f only
RndW	int	$clog2(MaxRound+1)	Representing up to MaxRound
Share	int	EnMasking ? 2 : 1
RhoOffset	int	undefined	Rho ====================================================================== As RhoOffset[x][y] is considered as variable int in VCS, it is replaced with generate statement. Revised to meet verilator lint. Now RhoOffset is 1-D array
PiRotate	int	undefined	rho Commented out entire rho function due to VCS elaboration error. (z-RhoOffset[x][y]%W) isn't considered as a constant in VCS. Even changing it to W-RhoOffset[x][y]%W and assign to ShiftAmt creates same error. Offset : Look at Table 2 in FIPS PUB 202 localparam int RhoOffset [5][5] = '{ //y 0 1 2 3 4 x '{ 0, 36, 3, 105, 210},// 0 '{ 1, 300, 10, 45, 66},// 1 '{ 190, 6, 171, 15, 253},// 2 '{ 28, 55, 153, 21, 120},// 3 '{ 91, 276, 231, 136, 78} // 4 }; rotate bits of each lane by offset 1. rho[0,0,z] = A[0,0,z] 2. Offset swap a. (x,y) := (1,0) b. for t [0..23] i. rho[x,y,z] = A[x,y,z-(t+1)(t+2)/2] ii. (x,y) = (y, (2x+3y)) function automatic box_t rho(box_t state); box_t result; for (int x = 0 ; x < 5 ; x++) begin for (int y = 0 ; y < 5 ; y++) begin for (int z = 0 ; z < W ; z++) begin automatic int index_z; index_z = (z-RhoOffset[x][y])%W; result[x][y][z] = state[x][y][(z-RhoOffset[x][y])%W]; end end end return result; endfunction : rho pi rearrange the position of lanes pi[x,y,z] = state[(x+3y),x,z]
RC	logic [63:0]	undefined	iota XOR (x,y) = (0,0) with Round Constant (RC) RC parameter: Precomputed by util/keccak_rc.py. Only up-to 0..L-1 is used RC = '0 RC[2*j-1] = rc(j+7rnd) rc(t) = 1. t%255 == 0 -> 1 2. R[0:7] = 'b10000000 3. for i = [1..t%255] a. R = 0

Types

Name	Type	Description
box_t	logic [4:0][4:0][W-1:0]	(x,y,z) state
lane_t	logic [W-1:0]	(z)
plane_t	logic [4:0] [W-1:0]	(x,z)
slice_t	logic [4:0][4:0]	(x,y)
sheet_t	logic [4:0][W-1:0]	(y,z) identical to plane_t
row_t	logic [4:0]	(x)
col_t	logic [4:0]	(y) identical to row_t

Functions

• bitarray_to_box (logic [Width-1:0]) return (box_t)

• box_to_bitarray (box_t) return (logic [Width-1:0])

• theta (box_t) return (box_t)

• pi (box_t) return (box_t)

• chi (box_t) return (box_t)