proof-of-reserves-v2

Background

OKX launches Proof of Reserves (PoR) to improve the security and transparency of users' assets. These tools will allow users to independently audit OKX's Proof of Reserves and verify OKX's reserves exceed the exchange's known liabilities to users, in order to confirm the solvency of OKX.

Technical Specs

The technical details can be found in the technical specs doc.

Liabilities

OKX's PoR uses Zero-knowledge (ZK) Merkle Sum Tree technology to allow each user to independently review OKX's digital asset reserve on the basis of protecting user's privacy. We use Plonky2 to build the proofs of users' assets using a Merkle Sum Tree. A detailed documentation of the technical solution can be found in the technical specs doc.

How to Run

• generate test data

file_num=10
per_file_account_num=131072 # multiple of 1024, the batch size

# test data will be generated to ./test-data/user-data
rm -rf ./test-data/user-data
mkdir -p ./test-data/user-data
python3 scripts/gen_test_data.py ${file_num} ${per_file_account_num}

• prove

cfg_dir_path="config"

cp ${cfg_dir_path}/default.toml ${cfg_dir_path}/local.toml

# edit local.toml such that the field "user_data_path" to "test-data/user-data"
sed -i '' 's|/opt/data/zkpor/users/|test-data/user-data|g' config/local.toml

output_proof_dir_path="./test-data/proof"

cargo run --release --package zk-por-cli --bin zk-por-cli prove --cfg-path ${cfg_dir_path} --output-path ${output_proof_dir_path}

• verify global proof

Note: this cmd will rebuild the circuit, instead of using the circuit provided in the proof file. Hence, the latency is longer but is more secure, i.e, 30 minutes in 8GB memory, 10 minutes in 16GB, 3 minutes in 32GB.

global_proof_path="./test-data/proof/sum_proof_data.json"

cargo run --features zk-por-core/verifier --release --package zk-por-cli --bin zk-por-cli verify-global --proof-path ${global_proof_path}

• batch verify user proofs

# to verify all accounts
user_proof_path_pattern="./test-data/proof/user_proofs/*.json"

# to verify one account with ${accountID}
# user_proof_path_pattern="./test-data/proof/user_proofs/${accountID}.json"

cargo run --features zk-por-core/verifier --release --package zk-por-cli --bin zk-por-cli verify-user --global-proof-path ${global_proof_path} --user-proof-path-pattern ${user_proof_path_pattern}

• verify both the global proof and a user proof

Note:

1. The cmd will NOT rebuild the circuit. Instead, it directly uses and trusts the circuit in the proof file. So the verification is fast, but a user needs to incur a weaker trust assumption.
2. The cmd will auto-detect sum_proof_data.json and *_inclusion_proof.json in the same directory of the binary for the verification.

cargo build --features zk-por-core/verifier --release --package zk-por-cli --bin zk-por-cli
mkdir -p tmp/
cp target/release/zk-por-cli tmp/
cp test-data/proof/user_proofs/$(ls test-data/proof/user_proofs | head -n 1) tmp/user_inclusion_proof.json
cp $global_proof_path tmp/sum_proof_data.json
./tmp/zk-por-cli
rm -rf tmp

• print commit hash

cargo run --release --package zk-por-cli --bin zk-por-cli show-commit-hash

cli tool

./target/release/zk-por-cli --help

Code Coverage

The code test coverage report is auto generated and hosted at codecov_report.

Docker

docker build -t okx_por_v2 -f docker/Dockerfile .