Intro

DCRM SDK is a distributed key generation and distributed signature module that forms the cornerstone of decentralized value exchange. This technology was developed for over a year, with the feedback of 4 leading cryptographers: Rosario Gennaro, Steven Goldfeder, Pascal Paillier, Louis Goubin.

When used in context of blockchain, this module can serve as a non-custodial solution, a keyless wallet, a component to an interoperable solution, and more. Please read the Wiki for more information.

This SDK allows you to connect to DCRM's network directly in either:

1. a 2+1 configuration where you form a private group with 2 fusion nodes and your own node.
2. a local configuration where you can set any ownership of nodes in your group.

This library contains 2 functions:

1. Distributed key generation which returns the public key (dcrm_genPubkey)
2. Distributed signing of transactions (dcrm_sign)

Note: dcrm-sdk is considered beta software. We make no warranties or guarantees of its security or stability.

Prerequisites

1. Linux terminal
2. Golang

Setting Up

Clone The Repository

To get started, launch your terminal and download the latest version of the SDK.

mkdir -p $GOPATH/src/github.com/fsn-dev

cd $GOPATH/src/github.com/fsn-dev

git clone https://github.com/fsn-dev/dcrm-sdk.git

Switch to Directory

cd dcrm-sdk

Build

Next compile the code. Make sure you are in /dcrm-sdk directory.

make

Run

Open access to the APIs by running the compiled code. Again, make sure you are in the /dcrm-sdk directory.

./bin/cmd/gdcrm

The gdcrm will provide two RPC APIs:

1. dcrm_genPubkey
2. dcrm_sign

The default RPC port is port 5559.

JSON RPC API

dcrm_genPubkey

This API generates a public key in distributed fashion by the P2P group.

Parameters

None

Return

error - Error info.

pubkey - DCRM public key generated by the P2P group.

Example

// Request

curl -X POST -H "Content-Type":application/json --data '{"jsonrpc":"2.0","method":"dcrm_genPubkey","params":[],"id":67}' http://127.0.0.1:5559

// Result

{
"pubkey":"049ac626ee0f0f79a49d6ed37f14ff2ad4e4f45fddf6e5293bcaa6a607e5392b49dde27a8f0602e23bc5fa0b847bd28d46e2f2d1d0d8cf59514785e4276b28de9d"
}

dcrm_sign

This API generates a signature in distributed fashion by the P2P group.

Parameters

1. DATA,pubkey - the pubkey from dcrm_genPubkey request.
2. String,|HexNumber|TAG - the hash needing signature. The format is the original 32-bit hexadecimal string appended to the characters "0x".
   For example: 0x19b6236d2e7eb3e925d0c6e8850502c1f04822eb9aa67cb92e5004f7017e5e41.

Return

error - Error info.

rsv - The signature string generated in distributed fashion by the P2P group.

Example

// Request

curl -X POST -H "Content-Type":application/json --data '{"jsonrpc":"2.0","method":"dcrm_sign","params":["049ac626ee0f0f79a49d6ed37f14ff2ad4e4f45fddf6e5293bcaa6a607e5392b49dde27a8f0602e23bc5fa0b847bd28d46e2f2d1d0d8cf59514785e4276b28de9d","0x19b6236d2e7eb3e925d0c6e8850502c1f04822eb9aa67cb92e5004f7017e5e41"],"id":67}' http://127.0.0.1:5559

// Result

{
"rsv":"FFBB398B95ED2ED308B0FE87BC254FFC2C9957742EA05C18A1411C672B74FBDF6FBD6F4915799F2B4186192581D4506039ADEB79C8EB954E779901FDB9575C8301"
}

Run Local

The SDK can also be configured to run locally, where the user can control ownership of all nodes in the P2P group.

Run bootnode

./bin/cmd/bootnode --genkey ./bootnode.key

The Default setup parameters are:
1) addr: 5550
2) group: 0 (group mode)
3) nodes: 3 (nodes Number form a group)
./bin/cmd/bootnode --nodekey ./bootnode.key --addr :5550 --group 0 --nodes 3

will print bootnode which use for run node with args --bootnodes
bootnode key such as enode://16ab118525ec559dde2640b513676b8df7368aac3a80cc5c9d9e8b9c71781c09103fe3e8b5dd17bf245f0c71b891ec4848b142852763ab2146a1e288df15da40@[::]:5550

Run nodes (3 nodes at least)

The Default setup parameters are:

1. nodekey: node.key
2. rpcport: 5559
3. port: 5551
4. bootnodes: "enode://200cb94957955bfa331ce14b72325c39f3eaa6bcfa962308c967390e5722f6fda0f6080781fde6a025a6280fbf23f38ca454e51a6b75ddbc1f9d57593790545a@47.107.50.83:5550"

Note: If you want to reboot a node, please wait 1 minute after closing node before restarting the node.

Setup using default parameters:

./bin/cmd/gdcrm
./bin/cmd/gdcrm --genkey node.key

Setup with custom parameters:

./bin/cmd/gdcrm --rpcport 9012 --bootnodes "enode://16ab118525ec559dde2640b513676b8df7368aac3a80cc5c9d9e8b9c71781c09103fe3e8b5dd17bf245f0c71b891ec4848b142852763ab2146a1e288df15da40@192.168.1.104:12340" --port 12341 --nodekey "node1.key"