Strong, quick, and extensible security solutions are required as blockchain technology is utilised more and more in financial systems to guarantee that transactions are honest, genuine, and can’t be challenged. This paper proposes a secure and light-weight security mechanism for financial operations using blockchain based on Elliptic Curve Cryptography (ECC). The paper focusses largely on employing curves like secp256k1 and Curve25519 to create secure keys using the Elliptic Curve Digital Signature Algorithm (ECDSA) to verify that transactions are genuine, therefore implementing ECC. In terms of latency, speed, signature size, gas cost, and energy consumption, the ECC-based system is evaluated against RSA/DSA. It works with Hyperledger and Ethereum blockchains. The findings indicate significant increases in speed and scale, which supports ECC as the optimal approach to secure and efficient create blockchain-based financial applications.