This is a Substrate-based blockchain that implements the ISO-8583 standard for financial transactions. It is a proof of concept that demonstrates a way to implement a custom runtime module that can be used to build a blockchain that integrates with an existing financial system that uses the ISO-8583 standard.

An integral part of this PoC is the PCIDSS compliant trusted oracle and payment processor server located at payment-processor.

There are some important assumtions and notes you should be aware of before testing this PoC:

• that it is a PoC and should not be used in production
• chain relies on the trusted oracle and payment processor server and serves as the settlement/extension layer of the existing financial system
• single source of truth is the offchain ledger, for the sake of simplicity. In the future, it would be possible to implement a more complex system where the on-chain balances are more important.
• oracles are in a semi-trusted environment, i.e. they are trusted to sign transactions, but not to decide on the validity of the transactions. This is done by the payment processor.
• the payment processor is a trusted entity that is responsible for the finality of the transactions. It is PCIDSS compliant and is responsible for the security of the funds.

Make sure you have the necessary environment for Substrate development. If not, please refer to the official document.

cargo build --release

./target/release/iso8583-chain --dev --tmp -loffchain-worker

Docker:

# Ready to use docker image
docker run -it -p 9944:9944 kingleard/iso8583-chain --dev --tmp --unsafe-rpc-external --rpc-cors=all --rpc-methods=unsafe -loffchain-worker

# Build docker image MacOS (M1)
docker build --platform linux/x86_64 -t iso8583-chain .

# Build docker image Linux
docker build -t iso8583-chain .

# Run docker image MacOS (M1)
docker run --platform=linux/x86_64 -it -p 9944:9944 iso8583-chain:latest --dev --tmp --unsafe-rpc-external --rpc-cors=all --rpc-methods=unsafe -loffchain-worker

# Run docker image Linux
docker run -it -p 9944:9944 iso8583-chain:latest --dev --tmp --unsafe-rpc-external --rpc-cors=all --rpc-methods=unsafe -loffchain-worker

First and foremost, insert the offchain worker key by running this command:

curl -H "Content-Type: application/json" \
 --data '{ "jsonrpc":"2.0", "method":"author_insertKey", "params":["'"iso8"'", "'"news slush supreme milk chapter athlete soap sausage put clutch what kitten"'", "'"0xd2bf4b844dfefd6772a8843e669f943408966a977e3ae2af1dd78e0f55f4df67"'"],"id":1 }' \
"https://localhost:9944"

Note that the above private key is used for demo purposes, i.e the trusted oracle and payment processor API expect this key to sign requests from offchain worker.

# Run check
cargo check --features runtime-benchmarks
# Run all tests: unit tests, integration tests, and doc tests
cargo test --workspace --all-features
# Run clippy
cargo clippy --workspace --all-targets --all-features
# Run fmt
cargo +nightly fmt --all --check
# Run code coverage
cargo tarpaulin --workspace --all-features

This is the high-level overview of components and how they interact: