In the times when conventional identity systems are being placed under constant threat of data leakage and centralized control, this research introduce a decentralized identity management system providing users with the ability to independently generate, suppress, and supervise digital identities without appealing to leading authorities. Developed on Flask (Python) backend and a frontend based on HTML, CSS and JavaScript, the system is using RSA public-key cryptography and SHA-256 hashing to provide safe message and documents signing with tamper-proof validation. Its integration with the blockchain technology is one of the significant features which immutably logs identity lifecycle events in the distributed ledgers and therefore bring transparency, auditing, and infallibility to processes. The proposed system shows password protected identity generation, cross platform signature authentication, secure document authentication and friendly user interface for interaction. The system was put to test with different combinations of signed documents and messages in different environments and platforms and was able to deliver accurate signature validation and tamper detection all the time.