Time lock script for Nervos Network

This is a lock script (smart contract) allows user to avoid consumption of a cell before specified time. After time limit, user still have to sign the transaction with their private key to consume the cell.

Lock argument

Arguments format:

| Lock argument | Time limit |
    20 bytes       8 bytes

Lock argument is same as that used for secp256k1_blake160_sighash_all system script.

Time limit is a big endian u64, represents an absolute Unix time stamp in milliseconds.

Unlock proof

To unlock a cell with this script, user have to append some block headers to the header_deps field of transaction as time proof. If all those headers' time stamp is earlier than the time limit, the cell won't be unlocked.

This script needs three cell dependencies:

• The script cell itself.
• The secp256k1_blake2b_sighash_all_dual shared library.
• The specs/cells/secp256k1_data system script/cell.

Building

Build contracts:

capsule build

Or in release mode:

capsule build --release

Run tests:

capsule test

Build shared library:

cd ckb-miscellaneous-scripts
make all-via-docker

ckb-miscellaneous-scripts/build/secp256k1_blake2b_sighash_all_dual is what we want.