SecureLayer: A Multi-Layered Architecture for Tamper-Proof File Sharing via Blockchain-Anchored Steganography and Visual Cryptography

Safeguarding file-sharing systems against advanced cyberthreats is crucial in this digital era. When it comes to cyber attacks, traditional encryption frequently fails. For tamper-proof data transfers, we suggest SecurChain, a multi-layered system that combines blockchain, adaptive steganography, and k,n-threshold visual cryptography. Dynamic LSB embedding reduces detectability by 40% by hiding sensitive information behind any harmless cover files (audio, images). Visual cryptography is used to divide the concealed data into n shares, removing single-point weaknesses by needing $k$ combined pieces for reconstruction. With a latency of less than three seconds, blockchain smart contracts provide integrity and traceability by permanently recording each transaction. PSNR greater than $42 \text{dB}, 98 \%$ steganalysis resistance, and less than 10% storage overhead were attained through thorough testing. A Tkinter GUI enables intuitive share management and blockchain auditing. SecureLayer complies with regulations such as the General Data Protection Regulation (GDPR) and prevents illegal access, manipulation, and data breaches. This universal solution bridges security and usability, offering robust protection for modern digital ecosystems.