Library with support for de/serialization, parsing and executing on data structures and network messages related to Bitcoin and other blockchain-based currencies.For JSONRPC interaction with Bitcoin Core, it is recommended to use rust-jsonrpc which uses the underlying strason library which parses decimal numbers as strings, preventing precision errors.To use rust-bitcoin, just add the following to your Cargo.toml.This library must not be used for consensus code (i.e.fully validating blockchain data).It technically supports doing this, using the feature-gated script parser, but doing so is very ill-advised because there are many deviations, known and unknown, between this library and the Bitcoin Core reference implementation.In a consensus based cryptocurrency such as Bitcoin it is critical that all parties are using the same rules to validate data, and this library is simply unable to implement the same rules as Core.Given the complexity of both C++ and Rust, it is unlikely that this will ever be fixed, and there are no plans to do so.

Of course, patches to fix specific consensus incompatibilities are welcome.Currently the documentation is very sparse.Patches to add usage examples and to expand on existing docs would be extremely appreciated.ethereum terms and conditionsPatches which add support for non-Bitcoin cryptocurrencies by adding constants to existing enums (e.g.bitcoin reichto set the network message magic-byte sequence) are welcome.bitcoin poker aceAnything more involved will be considered on a case-by-case basis, as the altcoin landscape includes projects which frequently appear and disappear, and are poorly designed anyway and keeping the codebase maintainable is a large priority.ethereum goal

In general, things that improve cross-chain compatibility (e.g.support for cross-chain atomic swaps) are more likely to be accepted than things which support only a single blockchain.bitcoin mining israelJoin our Telegram Channel!bitcoin reuters codeGet Bitcoin News stories in Telegram × Dismissbitcoin pools reddit)submitted by π Rendered by PID 14143 on app-162 at 2017-06-24 12:40:46.525318+00:00 running 3522178 country code: SG.bitcoin successful double spendPairing cryptography is an exciting area of research, and an essential component of Zcash's zkSNARKs — proofs that transactions are valid without requiring users to reveal private information.bitcoin transaction basics

Earlier this year we also used zkSNARKs to make Bitcoin's first zero-knowledge contingent payment!One of our goals going forward is to better explain how these tools work, and to make them more accessible to the public.As a first step, we're starting development of a pairing cryptography library for Rust called "bn".Pairing cryptography is important for zkSNARKs, but what exactly is it?Elliptic Curves Regular elliptic curve constructions like secp256k1 — used in Bitcoin — are designed for things like digital signatures.The points on the curve form a cyclic group: they can be added together and multiplied by scalars.It is believed to be infeasible to find the multiplicand given a point and the product point, called the "elliptic curve discrete logarithm problem".This asymmetry (the ease of multiplying but the difficulty of the reverse) is used to make a number of useful tools and protocols.Diffie-Hellman key exchange is a simple example: Alice multiplies Bob's public key by her (scalar) private key, and vice versa, to find a shared secret in the presence of an eavesdropper.

This key exchange protocol can be extended to three parties, but requires two rounds: for parties , , and , obtains the shared secret by having send his public key to , who multiplies it by her private key and sends the result to , who can then derive the shared secret by multiplying it by her private key.Pairing cryptography Pairing cryptography is an extension of these concepts.Now imagine that we have two cyclic groups: \(G_{1}\) and \(G_{2}\), written additively, and a mapping to a third cyclic group of the form e: \(G_{1} \times G_{2} \rightarrow G_{T}\), where \(G_{T}\) is written multiplicatively.If this mapping is bilinear, then: \(e(a g_{1}, b g_{2}) = e(g_{1}, g_{2})^{ab}\) where \(a\) and \(b\) are scalars and \(g_{1}\) and \(g_{2}\) are generators for their respective groups.Essentially, a scalar multiplication of one of the first two group elements is equivalent to an exponentiation of the final group element.Joux's key agreement protocol Let's apply pairing cryptography to the three-party key exchange scenario above.

Using pairings, we can perform the exchange in one round.Each party \(P\) publishes their public key \(P^{pk} = (P^{sk} g_{1}, P^{sk} g_{2})\) and keeps their private key \(P^{sk}\) secret.All of the parties \(A, B, C\) can compute the same shared secret using the bilinear pairing function: Alice Computes Bob Computes Carol Computes All equivalent to Or, if you prefer code, check out an example from our new library: = ( = ( = ( (, ) = ( * &, * & (, ) = ( * &, * & (, ) = ( * &, * & = (&, &) ^ &; = (&, &) ^ &; = (&, &) ^ &; !(bn The "bn" crate is a Rust language library for performing these pairing operations using a cryptographic construction designed by our scientists in [BCGTV14].It uses a Barreto-Naehrig elliptic curve tuned for use in zkSNARKs.The library is new and incomplete and shouldn't be used in production software, but it is a nice step forward in our goal of making this new kind of cryptography more widely understood and easier to use.