Special subsets of addresses for blockchains using the secp256k1 curve

TL;DR

This paper explores vulnerabilities in blockchain address private keys, extending previous findings by applying similar attacks to various cryptocurrencies and analyzing the security implications of special address subsets.

Contribution

It generalizes prior private key recovery attacks to multiple cryptocurrencies and characterizes address subsets that are vulnerable to such attacks.

Findings

Certain address subsets are vulnerable to private key recovery attacks.

The attack techniques can be applied across multiple blockchain platforms.

Exhaustive search methods reveal addresses with weak private key security.

Abstract

In 2020 Sala, Sogiorno and Taufer have been able to find the private keys of some Bitcoin addresses, thus being able to spend the cryptocurrency linked to them. This result was unexpected, since the recovery of non-trivial private keys for blockchain addresses is deemed to be an infeasible problem. In this paper we widen this analysis by mounting a similar attack to other small subsets of the set of private keys. We then apply it to other blockchains as well, examining Ethereum, Dogecoin, Litecoin, Dash, Zcash and Bitcoin Cash. In addition to the results, we also explain the techniques we have used to perform this exhaustive search for all the addresses that have ever appeared in these blockchains.