hsslms 0.0.1

Leighton-Micali Hash-Based Signatures

python-hsslms

This is an implementation of Leighton-Micali Hash-Based Signatures in Python according to RFC 8554.

The implementation is meant as a reference and for educational purposes.

The implementation provides 4 classes:

• LM-OTS One-Time Signatures. These are one-time signatures; each private key MUST be used at most one time to sign a message.
• Leighton-Micali Signatures (LMS). This system holds a fixed number of one-time signatures, i.e. LM-OTS.
• Hierarchical Signatures (HSS). This system uses a sequence of LMS.
• Persistent Hierarchical Signatures (PersHSS). The same as HSS except that the private key is stored in an encrypted file.

Installation

python3 -m pip install hsslms

Example Usage

LM-OTS

from os import urandom
from hsslms import LM_OTS_Priv

# generate a one-time private key
sk = LM_OTS_Priv(LMOTS_ALGORITHM_TYPE.LMOTS_SHA256_N32_W2, urandom(16), 0)
# sign a message with the private key
signature = sk.sign(b'abc')
# compute the related public key
vk = sk.gen_pub()
# verify the signature, if invalid an exception will be raised
vk.verify(b'abc', signature)

LMS

from os import urandom
from hsslms import LMS_Priv

# generate a private key
sk = LMS_Priv(LMS_ALGORITHM_TYPE.LMS_SHA256_M32_H10, LMOTS_ALGORITHM_TYPE.LMOTS_SHA256_N32_W8)
# sign a message with the private key, in total 2^10 signatures are available
signature = sk.sign(b'abc')
# compute the related public key
vk = sk.gen_pub()
# verify the signature, if invalid an exception will be raised
vk.verify(b'abc', signature)

HSS

from os import urandom
from hsslms import HSS_Priv

# generate a private key
sk = HSS_Priv([LMS_ALGORITHM_TYPE.LMS_SHA256_M32_H10]*2, LMOTS_ALGORITHM_TYPE.LMOTS_SHA256_N32_W1)
# sign a message with the private key, in total 2^20 signatures are available
signature = sk.sign(b'abc')
# compute the related public key
vk = sk.gen_pub()
# verify the signature, if invalid an exception will be raised
vk.verify(b'abc', signature)

Performance Measurements

The measurements are done on a Ryzen 5800X, where multiprocessing features are used with 6 cores.

Key Generation

Key-Type	w	Time[s]	#Signatures	Size of Signature
H10	1/2/8	0.5 / 0.3 / 0.9	1024	8848 / 4624 / 1456
H15	1/2/8	15.7/9.5/23.3	32768	9008 / 4784 / 1616
H20	1/2/8	- / - / 806	1048576	- / - / 1776
H10/H10	1/2/8	1.4 / 0.7 / 3.2	1048576	17748 / 9300 / 2964
H10/H15	1/2/8	6.0 / 9.7 / 24.5	33554432	17908 / 9460 / 3124
H15/H15	1/2/8	12.9 / 14.0 / 50.8	1073741824	18068 / 9620 / 3284

Performance of Signature Generation:

Key-Type	w	Time[s]
H15	1/2/8	0.04 / 0.01 / 0.005

Performance of Signature Verification:

Key-Type	w	Time[s]
H15	1/2/8	0.04 / 0.01 / 0.005

License

MIT