pygroupsig

Welcome to pygroupsig, an extensible library for group signatures. Below, you can find basic information about how to use the library.

Compilation

This library has been developed from scratch in Python except for mcl. We have built a wrapper around the original mcl library written in C/C++ using Python ctypes.

The library has type hints to ease the development of new schemes. If you encounter any errors or have suggestions for improvements, please feel free to open a PR or an issue.

To build mcl, run the following commands.

git clone https://github.com/herumi/mcl.git
cd mcl
cmake -B build .
make -C build

You need to export an environment variable, MCL_LIB_PATH, pointing to the lib folder

export MCL_LIB_PATH=$PWD/mcl/build/lib

Usage

You can instantiate the different schemes using the group class factory or by directly using the specific class for each scheme:

from pygroupsig import group, GroupBBS04, key, MemberKeyBBS04

## Two variants

# Method1
g = group("bbs04")() # Note: `group` function returns a class, not an instance
# Method2
# g = GroupBBS04()

g.setup()
gk_b64 = g.group_key.to_b64()

# Client side: create a group to use join protocol; you need to set the group_key (public)
gm = group("bbs04")()
gm.group_key.set_b64(gk_b64)

# Method 1
mk = key("bbs04", "member")()
# Method 2
# mk = MemberKeyBBS04()

# Test join protocol that take into account each scheme needs
msg2 = None
seq = gm.join_seq()
for _ in range(0, seq + 1, 2):
    msg1 = g.join_mgr(msg2) # Group manager side
    msg2 = gm.join_mem(msg1, mk) # Member side

s_msg = gm.sign("Hello world!", mk)
v_msg = gm.verify("Hello world!", s_msg["signature"])

The functions setup, join_mgr, join_mem, sign and verify are common to all schemes. Some schemes also implement additional functionalities:

BBS04

• open

PS16

• open
• open_verify

CPY06

• open
• reveal
• trace
• prove_equality
• prove_equality_verify
• claim
• claim_verify

KLAP20

• open
• open_verify

GL19

• blind
• convert
• unblind

DL21

• identify
• link
• link_verify

DL21SEQ

• identify
• link
• link_verify
• seqlink
• seqlink_verify

Tests

Run the following command to execute the tests:

python -m unittest

Acknowledgement

This work was supported by the European Commission under the Horizon Europe funding programme, as part of the project SafeHorizon (Grant Agreement 101168562). Moreover, it was supported by the European Commission under the Horizon Europe Programme as part of the HEROES project (Grant Agreement number 101021801) and the European Union's Internal Security Fund as part of the ALUNA project (Grant Agreement number 101084929). Views and opinions expressed are however those of the author(s) only and do not necessarily reflect those of the European. Neither the European Union nor the granting authority can be held responsible for them.

• Based on piotrszyma/mcl-python bindings for mcl.
• Based on herumi/mcl.
• Based on spirs/libgroupsig and IBM/libgroupsig

LICENSE

Copyright (c) 2024 Cybersecurity and Privacy Protection Research Group (GiCP), part of Consejo Superior de Investigaciones Científicas (CSIC). All rights reserved.
This work is licensed under the terms of the MIT license.

For a copy, see LICENSE