PHOTO CHAIN A BLOCKCHAIN BASED SECURE PHOTO SHARING FRAMEWORK FOR CROSS-SOCIAL NETWORK

Abstract- In recent years, online social networks (OSNs) have become increasingly popular due to the rapid development of mobile applications and the explosive growth in online interaction with the growth and accessibility of technology and internet, the ease of posting and sharing photos on social networking services (SNSs) has increased exponentially. The privacy of online photos is often protected carefully by security mechanisms. However, these mechanisms will lose effectiveness when someone spreads the photos to other platforms the illegal disclosure of user’s private data can cause damaging consequences and even threaten the safety of user’s life In contrast to security mechanisms running separately in centralized servers that do not trust each other, our framework achieves consistent consensus on photo dissemination control through carefully designed smart contract-based protocols. Considering the possible privacy conflicts between owners and subsequent re-posters in cross social network photo sharing, we design a dynamic privacy policy generation algorithm that maximizes the flexibility of re-posters without violating formers' privacy. The extensive experiments and security analysis demonstrate the security, efficacy and efficiency of our proposed framework.