Blockchain systems rely on decentralized ledgers and strong security guarantees. A key requirement is non-repudiation, which prevents denial of transaction authorship and supports integrity of recorded data. This work surveys digital signature schemes used in blockchain platforms and analyzes how they deliver non-repudiation and contribute to overall system security. We examine representative scheme families and their cryptographic foundations, security assumptions, and properties relevant to deployment, including unforgeability, resistance to malleability, support for aggregation and multisignature or threshold settings, key and signature sizes, and verification cost. Using these criteria, we compare the suitability of different designs for consensus protocols, smart contract constraints, and resource limits. We highlight practical tradeoffs that affect throughput, storage, scalability, and attack surfaces, and summarize benefits and limitations of each scheme in blockchain contexts. The study underscores that carefully chosen digital signatures are central to achieving non-repudiation and preserving information integrity, and it outlines implementation considerations and open directions such as interoperability and post-quantum readiness.