Institute of Electrical & Electronic Engineers
The authors propose a scheme for application service providers that will allow them to provide a secure and traceable online image sharing service. To this end, a service provider needs to achieve security against unauthorized read access and traceability in the event of unauthorized write access. Digital watermarking is a promising approach for achieving traceability. However, if an image is encrypted using a cryptographic key shared between authorized users for security, it is difficult for the service provider to flexibly embed a digital watermark into the encrypted image. To overcome this encryption limitation, they propose a novel solution based on the Secure Multiparty Computation (SMC) protocol and Secret Sharing Scheme (SSS).