Mastering Blockchain - Second Edition

Limitations in cryptographic functions

Cryptography used in the Bitcoin blockchain is exceptionally secure and has stood the test of time. In other blockchains, similar security techniques are used and are also very secure. However, specific security issues such as the possibility of generation and usage of duplicate signature nonces in elliptic curve digital signature schemes (leading to private key recovery attack), collisions in hash functions, and a possibility of quantum attacks that may break the underlying cryptographic algorithms remain an exciting area of research.