EMP-zk

Which version do I want?

• Existing projects pinned to a published release: stay on v0.3.x — python3 install.py --tool=v0.3.x --ot=v0.3.x --zk=v0.3.x reproduces the prior emp-zk line. Bug fixes will be backported.
• New projects, or willing to migrate: track main — built against the C++20 BooleanContext line of emp-tool / emp-ot v1.0. emp-zk-bool is a native BooleanContext (ZKBoolContext) driven by an explicit ZKBoolSession handle — no global backend; gadgets receive the session and circuit values are Bit_T<ZKBoolContext> / Int_T<…>. emp-zk-arith still keeps its own ZKFpExec::zk_exec singleton (staged). BaseCot and TwoKeyPRP (which moved out of emp-ot main) are vendored locally under emp-zk/emp-vole/, and the GaloisFieldPacking::base[] array that ram-zk indexes is provided by a small ramzk_gf_base() helper. The full emp-zk umbrella (bool / arith / vole / ram / floats / lowmc) builds and tests pass end-to-end.

Protocols

The code in this repo implements a fast, scalable, communication-efficient zero-knowledge proof protocol for Boolean/arithmetic circuits and polynomials. The protocols are described in Wolverine, Quicksilver and Mystique.

Requirements

• CMake ≥ 3.21
• A C++20 compiler
• OpenSSL (≥ 1.1)
• emp-tool / emp-ot at the matching release line

Build and install

cmake -B build -DCMAKE_BUILD_TYPE=Release
cmake --build build -j
sudo cmake --install build      # respects CMAKE_INSTALL_PREFIX

If emp-tool / emp-ot are in sibling source trees rather than installed, point CMake at their build directories:

cmake -B build -DCMAKE_BUILD_TYPE=Release \
    -Demp-tool_DIR=/path/to/emp-tool/build \
    -Demp-ot_DIR=/path/to/emp-ot/build
cmake --build build -j

Consuming from another CMake project

After cmake --install build:

find_package(emp-zk 1.0 REQUIRED)
target_link_libraries(my-app PRIVATE emp-zk::emp-zk)

The emp-zk::emp-zk target transitively pulls in emp-ot::emp-ot and emp-tool::emp-tool.

Test

ctest --test-dir build --output-on-failure

Tests under test/bool/, test/arith/, test/vole/, and test/ram/ exercise every module end-to-end: Boolean / arithmetic ZK, polynomial / inner-product proofs, SHA-256 + LowMC circuits, edabit bool↔arith conversion, VOLE bootstrap (cope / lpn / base_svole / vole_triple / vole_f2k_triple), and RAM ZK (read-only, read-write, extended). Two-party tests are driven by the top-level ./run wrapper (spawns party 1 then party 2 on localhost).

For a two-machine run: ./bin/test_bool_<name> 1 <port> on host A and ./bin/test_bool_<name> 2 <port> on host B; edit the test source if the IP needs to be other than 127.0.0.1.

Performance

The test is done by two AWS EC2 m5.2xlarge servers with throttled network.

Throughput of circuit-based ZK protocol

All values are "million gates per second".

Boolean circuits

Threads	10 Mbps	20 Mbps	30 Mbps	50 Mbps	Localhost
1	5.1	7.8	8.6	8.6	8.6
2	6	10	12.9	14.3	13.6
3	6.3	10.9	14.5	17.3	18
4	6.4	11.4	15.1	19	19.4

Arithmetic circuits

Threads	100 Mbps	500 Mbps	1 Gbps	2 Gbps	Localhost
1	1.4	4.8	6.8	7.8	7.8
2	1.4	5.6	8.7	10.2	10.4
3	1.4	5.9	9.3	11.7	12.5

(Numbers measured on the v0.3.x line; main runs the same protocols, so re-measured numbers should be in the same ballpark.)

Acknowledgement, Reference, and Questions

Please send email to Xiao Wang (wangxiao1254@gmail.com).

License

Licensed under the Apache License, Version 2.0 — see LICENSE.