uranther

The Blockchain (distributed ledger technology)

What do you all think about writing a blockchain in Elixir? Being a functional language and having OTP in our arsenal, it seems it would be easier to get a block chain up-and-running quickly. We even have some good starting points for the consensus algorithm and hash trees:

Blockchain resources

Elixir community effort

exchain/exchain on GitHub
robinmonjo/coincoin

Background

Videos

DEVCON1: Understanding the Ethereum Blockchain Protocol - Vitalik Buterin

Topical

General

“Explainers” on core concepts like blockchains and smart contracts

Bitcoin

Bitcoin Block Chain developer reference

Ethereum

Books

Princeton Bitcoin Book
Blockchain Revolution: How the Technology Behind Bitcoin Is Changing Money, Business, and the World by Don Tapscott et al.
The Science of the Blockchain by Roger Wattenhofer
Mastering Bitcoin: Unlocking Digital Cryptocurrencies by Andreas M. Antonopoulos

White Papers

Benchmarks

These projects are in active (rapid!) development and in a variety of languages.

Ethereum
- Ethcore Parity (Rust)
- go-ethereum/Geth (Go)
- webthree-umbrella (C++)
- ethereumj (Java)
- pyethereum (Python)
- ethereum-client-haskell (Haskell) – looks stagnant
- ruby-ethereum (Ruby)
Hyperledger
- Fabric (Go)
- Sawtooth (Python)
- Juno (Haskell) – Smart Contracts Running on a BFT Hardened Raft
Stellar
- stellar-core (C++)

Academic Papers

Specific implementations

Bitcoin: A Peer-to-Peer Electronic Cash System
Ethereum Yellow Paper – formal specification

Meta-analysis

The Quest for Scalable Blockchain Fabric: Proof-of-Work vs. BFT Replication
Hiding Transaction Amounts and Balances in Bitcoin (zero knowledge proofs)
Misbehavior in Bitcoin: A Study of Double-Spending and Accountability (double-spending attack)

Distributed consensus

Proofs of “X”

Various methods of using blockchain technologies to prove something in a way that is cryptographically verifiable.

FOR CRYPTOCURRENCY

OTHER PROOFS

Proof of Elapsed Time (PoET)
Proof of Existence (or Publication)
Proof of Ownership
Proof of Integrity
Proof of Agreement
Proof of Receipt

Blockchain components

Distributed consensus algorithms

A fundamental problem in distributed computing and multi-agent systems is to achieve overall system reliability in the presence of a number of faulty processes. This often requires processes to agree on some data value that is needed during computation. Examples of applications of consensus include whether to commit a transaction to a database, agreeing on the identity of a leader, state machine replication, and atomic broadcasts. (Wikipedia)

raftex - Raft consensus
expaxos - Paxos consensus
rafute - Another implementation of Raft
dike - Paxos implementation in Erlang

Merkle (hash) trees

A hash tree or Merkle tree is a tree in which every non-leaf node is labelled with the hash of the labels or values (in case of leaves) of its child nodes. Hash trees are useful because they allow efficient and secure verification of the contents of large data structures. Hash trees are a generalization of hash lists and hash chains. (Wikipedia)

Elixir

merkle_tree — blog post
elixir-merkle

Erlang

merklet
Hash trees - Riak implementation
- hashtree.erl
- hashtree_tree.erl

Cryptography

Elixir

elixir-rsa - Erlang public_key cryptography wrapper
elixir-ecc - elliptic curve cryptography
elixir-mcrypt - NIF wrapper around libmcrypt
cryptex - library for encrypting/decrypting, signing/verifying data

Erlang

:crypto

Keywords: state machine replication, distributed cryptographic ledger, transaction log

87 comments

#wiki

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2022-06-07 08:56:48 UTC

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aesedepece

Hi everyone,

Good news for you: there’s already at least one successfully funded open source Elixir project in the blockchain space.

We are Stampery, a startup leveraging the power of the bitcoin and ethereum blockchains to create immutable proof of existence, integrity and ownership of any kind of data set.

In fact, we have been part of the last batch of the aforementioned Boost accelerator. I am pretty sure @IamCharlesHan knows my colleges Luis, Daniele and of course Tomasso and his celebrated cooking skills.

Stampery was funded with $600K from Draper & Associates, Blockchain Capital and Di-Ann Eisnor in 2015 Q3, shortly after presenting at TechCrunch Disrupt SF.

We used Elixir to build our distributed blockchain data anchoring architecture, best known as BTA. It allows us to embed as many data as we want in a single bitcoin or ethereum TX.

We are open sourcing our whole stack these days. We started by publishing our binary merkle tree Elixir implementation, which as @uranther mentioned is crucial for any blockchain project you may want to start out:

We will continue releasing the source code for more components of our stack in the next weeks, including the bitcoin and ethereum raw transaction composer modules.

Of course I will be more than happy to contribute to this exchain initiative. I’m aesedepece at Github.

Let’s see what we can come up with!

Post #12

uranther

Looking at the architectural diagram of Hyperledger, I tried to figure which modules would be suited to Elixir (highlighted yellow in the image) and which to Rust or the like (highlighted red). It seems Elixir could handle a large portion of these services, while leaving computation- and memory-intensive chaincode services to a faster computing language. That fast language could be Haskell or even Futhark. I wonder how juno compares to Ethcore Parity in chaincode/smart contract speed.

Maybe the ledger storage could be handled with Riak or a NewSQL database like VoltDB or CockroachDB? The event stream could be exposed through a WebSocket. Any other thoughts?

So a possible way forward is to build out Elixir services which replace those in Hyperledger. The idea being that we can write correct distributed systems code with fewer SLOC and which is easier to understand and reason about.

@aesedepece That’s awesome you are using Elixir for this exact purpose! I look forward to seeing more open source libraries released from Stampery. I am especially interested in these five types of proofs you provide:

Proof of Ownership
Proof of Existence
Proof of Integrity
Proof of Agreement
Proof of Receipt

I have some other feedback about the website and copy, but it doesn’t really fit in this thread

Post #13

robinmonjo

Hello all,

I made a “naive” blockchain in Elixir, inspired by existing implementations in JS and Haskell (links in the readme). I made this for educational purpose to improve my Elixir skills but this might (hopefully) be a good starting point.

Any feedbacks/contributions are welcome and you can let me know what you think here.

Regards,
Robin

Post #59

rps17

Hi uranter,

that’s a good idea. I’m learning Elixir/Phoenix and have great interest in cryptocurrencies, applications of blockchain.
I’ve found this article and think it is interesting
http://yosriady.com/2016/05/19/merkle-trees-in-elixir/

Post #14

uranther

Do you have any repository set up yet?

exchain/exchain on GitHub

I just created a new supervised mix project and put a tentative roadmap for the project.

Do you think it can all be done in Elixir / Erlang - any need for performant C code?

I think we can start implementing it in Elixir as non-fancy data structures until we need to start scaling it and optimizing bottlenecks. The “chaincode” or smart contracts portion should be done in Rust (or Futhark?) because that component must crunch numbers. It would be convenient to use the smart contracts virtual machine of Ethcore Parity, the latest Rust implementation of Ethereum, and likewise pluggable for that of Hyperledger Fabric or Sawtooth.

Post #31