[source]

Module prim_prince

Block Diagram of prim_prince

This module is an implementation of the 64bit PRINCE block cipher. It is a fully unrolled combinational implementation with configurable number of rounds. Optionally, registers for the data and key states can be enabled, if this is required. Due to the reflective construction of this cipher, the same circuit can be used for encryption and decryption, as described below. Further, the primitive supports a 32bit block cipher flavor which is not specified in the original paper. It should be noted, however, that the 32bit version is * not * secure and must not be used in a setting where cryptographic cipher strength is required. The 32bit variant is only intended to be used as a lightweight data scrambling device.

See also

prim_present, prim_cipher_pkg

References

Parameters
Name	Default	Description
DataWidth	64
KeyWidth	128
NumRoundsHalf	5	The construction is reflective. Total number of rounds is 2*NumRoundsHalf + 2
UseOldKeySched	1'b0	This primitive uses the new key schedule proposed in https://eprint.iacr.org/2014/656.pdf Setting this parameter to 1 falls back to the original key schedule.
HalfwayDataReg	1'b0	This instantiates a data register halfway in the primitive.
HalfwayKeyReg	1'b0	This instantiates a key register halfway in the primitive.

Ports
Name	Type	Direction	Description
clk_i	wire logic	input
rst_ni	wire logic	input
valid_i	wire logic	input
data_i	wire logic [DataWidth - 1 : 0]	input
key_i	wire logic [KeyWidth - 1 : 0]	input
dec_i	wire logic	input	set to 1 for decryption
valid_o	var logic	output
data_o	var logic [DataWidth - 1 : 0]	output

Assertions
Name	Kind	Description
prim_prince.SupportedWidths_A	immediate assert	////////////// assertions // ////////////// (((DataWidth == 64) && (KeyWidth == 128)) \|\| ((DataWidth == 32) && (KeyWidth == 64)))
prim_prince.SupportedNumRounds_A	immediate assert	((NumRoundsHalf > 0) && (NumRoundsHalf < 6))

Always Blocks

always_comb @(): pre-round XOR

always_comb @(): post-rounds