Feed for tag: crypto
An Overview of the Upcoming Multisignature Standard by Andrew Poelstra

ECDSA has been the preferred signature algorithm for most blockchain networks for verifying ownership and transfer of assets on the networks. However, this complex scheme that has been used in Bitcoin since 2008 started to show its limits. For example difficulties in producing multisignatures and added complexity in second layer Bitcoin networks like Lightning and crhoss-chain atomic swaps. Last year, a proposal called MuSig, or MultiSignature Scheme, was made. It offers many improvements over ECDSA and is probably one the most important cryptographic improvements to Bitcoin that would help increase privacy and efficiency in transactions.

Andrew Poelstra, one of the key researchers and co-author of the paper published a technical overview on this upcoming cryptographic scheme and its applications.

Monero Transaction Traceability

Monero is one of the leading privacy coins on the market. A recent paper called An Empirical Analysis of Traceability in the Monero Blockchain argued that it might not be as private as expected.

In this paper, we empirically evaluate two weaknesses in Monero’s mixin sampling strategy. First, about 62% of transaction inputs with one or more mixins are vulnerable to “chain-reaction” analysis — that is, the real input can be deduced by elimination. Second, Monero mixins are sampled in such a way that they can be easily distinguished from the real coins by their age distribution; in short, the real input is usually the “newest” input.

However some of the issues addressed in the paper have already been addressed by the monero dev team.

Velvet Forks
Blockchain forks have been a controversial subjects since the dawn of bitcoin, there’s two types of forks, one is called a soft fork, this adds more restrictions to the consensus on which the blocks are verified, a block that was deemed valid before the soft fork can be deemed invalid after it, while the other type of fork is called a hard forkm, and it is exactly the opposite, a hard fork loseens the restrictions on which the blocks are verified, so that a block that was deemed invalid before the hard fork can be deemed valid.
Simple Schnorr Multi Signatures With Applications to Bitcoin

Blockstream announced on their blog a paper they published, introducing MuSig a multi-signature scheme based on Schnorr signatures.

While this work is a result of our research into Schnorr signatures for Bitcoin, MuSig is a cryptographic construction that may be useful for other applications. The paper and this post primarily discuss the cryptographic properties of MuSig, and aren’t directly a proposal for Bitcoin.