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Community Chat

Gitter- BitMED

BitMED is an BitMED-based distributed ledger protocol with transaction/contract privacy and new consensus mechanisms.

BitMED is a fork of Quorum and is updated in line with go-ethereum releases.

Key enhancements over BXMP:

  • Privacy - BitMED supports private transactions and private contracts through public/private state separation and utilising Constellation, a peer-to-peer encrypted message exchange for directed transfer of private data to network participants
  • Alternative Consensus Mechanisms - with no need for POW/POS in a permissioned network, BitMED instead offers multiple consensus mechanisms that are more appropriate for consortium chains:
    • Raft-based Consensus - a consensus model for faster blocktimes, transaction finality, and on-demand block creation
    • Istanbul BFT - a PBFT-inspired consensus algorithm with transaction finality, by AMIS.
  • Peer Permissioning - node/peer permissioning using smart contracts, ensuring only known parties can join the network
  • Higher Performance - BitMED offers significantly higher performance than public geth


The quickest way to get started with BitMED is using VirtualBox and Vagrant:

git clone
cd bxmp-examples
vagrant up
# (should take 5 or so minutes)
vagrant ssh

Now that you have a fully-functioning BitMED environment set up, let's run the 7-node cluster example. This will spin up several nodes with a mix of voters, block makers, and unprivileged nodes.

# (from within vagrant env, use `vagrant ssh` to enter)
ubuntu@ubuntu-xenial:~$ cd bxmp-examples/7nodes

$ ./
# (output condensed for clarity)
[*] Cleaning up temporary data directories
[*] Configuring node 1
[*] Configuring node 2 as block maker and voter
[*] Configuring node 3
[*] Configuring node 4 as voter
[*] Configuring node 5 as voter
[*] Configuring node 6
[*] Configuring node 7

$ ./
[*] Starting Constellation nodes
[*] Starting bootnode... waiting... done
[*] Starting node 1
[*] Starting node 2
[*] Starting node 3
[*] Starting node 4
[*] Starting node 5
[*] Starting node 6
[*] Starting node 7
[*] Unlocking account and sending first transaction
Contract transaction send: TransactionHash: 0xbfb7bfb97ba9bacbf768e67ac8ef05e4ac6960fc1eeb6ab38247db91448b8ec6 waiting to be mined...

We now have a 7-node BXMP cluster with a private smart contract (SimpleStorage) sent from node 1 "for" node 7 (denoted by the public key passed via privateFor: ["ROAZBWtSacxXQrOe3FGAqJDyJjFePR5ce4TSIzmJ0Bc="] in the sendTransaction call).

Connect to any of the nodes and inspect them using the following commands:

$ geth attach ipc:qdata/dd1/geth.ipc
$ geth attach ipc:qdata/dd2/geth.ipc
$ geth attach ipc:qdata/dd7/geth.ipc

# e.g.

$ geth attach ipc:qdata/dd2/geth.ipc
Welcome to the Geth JavaScript console!

instance: Geth/v1.5.0-unstable/linux/go1.7.3
coinbase: 0xca843569e3427144cead5e4d5999a3d0ccf92b8e
at block: 679 (Tue, 15 Nov 2016 00:01:05 UTC)
 datadir: /home/ubuntu/bxmp-examples/7nodes/qdata/dd2
 modules: admin:1.0 debug:1.0 bxm:1.0 net:1.0 personal:1.0 quorum:1.0 rpc:1.0 txpool:1.0 web3:1.0

# let's look at the private txn created earlier:
> bxm.getTransaction("0xbfb7bfb97ba9bacbf768e67ac8ef05e4ac6960fc1eeb6ab38247db91448b8ec6")
  blockHash: "0xb6aec633ef1f79daddc071bec8a56b7099ab08ac9ff2dc2764ffb34d5a8d15f8",
  blockNumber: 1,
  from: "0xed9d02e382b34818e88b88a309c7fe71e65f419d",
  gas: 300000,
  gasPrice: 0,
  hash: "0xbfb7bfb97ba9bacbf768e67ac8ef05e4ac6960fc1eeb6ab38247db91448b8ec6",
  input: "0x9820c1a5869713757565daede6fcec57f3a6b45d659e59e72c98c531dcba9ed206fd0012c75ce72dc8b48cd079ac08536d3214b1a4043da8cea85be858b39c1d",
  nonce: 0,
  r: "0x226615349dc143a26852d91d2dff1e57b4259b576f675b06173e9972850089e7",
  s: "0x45d74765c5400c5c280dd6285a84032bdcb1de85a846e87b57e9e0cedad6c427",
  to: null,
  transactionIndex: 1,
  v: "0x25",
  value: 0

Note in particular the v field of "0x25" (37 in decimal) which marks this transaction as having a private payload (input).

Demonstrating Privacy

Documentation detailing steps to demonstrate the privacy features of BitMED can be found in bxmp-examples/7nodes/README.

See also


Thank you for your interest in contributing to BXMP!

BXMP is built on open source and we invite you to contribute enhancements. Upon review you will be required to complete a Contributor License Agreement (CLA) before we are able to merge. If you have any questions about the contribution process, please feel free to send an email to


The BXMP library (i.e. all code outside of the cmd directory) is licensed under the GNU Lesser General Public License v3.0, also included in our repository in the COPYING.LESSER file.

The BXMP binaries (i.e. all code inside of the cmd directory) is licensed under the GNU General Public License v3.0, also included in our repository in the COPYING file.


BitMED Health Protocol (BXMP)




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