Blockchain is the invention that permits digitally generated information to be allocated without being copied. Blockchain technology is the heart of the new internet (i.e., virtual currency). Emerging clever settlement structures over decentralized cryptocurrencies permit jointly suspicious events to transact competently without relying on third parties (i.e., the reason to provide wide security to blockchain technology). Cryptography has so many algorithms to provide security such as MD5, AES, RSA, SHA family, etc. Hash functions are extremely useful and appear in almost all information security applications, so hashing techniques are more secure among them. The authors are designing a new approach (i.e., SHA-512) in a local blockchain application. SHA-512 is a very secure algorithm that uses 64-bit words and operates on 1024-bit blocks. They are proving that SHA-512 is more collision-resistant than its predecessor with a few mathematical models.