Robust and Secure Watermarking for Propagation of Digital Multimedia by Paillier Homomorphic Cryptosystem With Arnold Transformation

Sharing of digital media over internet is becoming easier due to content authentication and security provided by digital watermarking. It also locates application in other fields like copyright protection, tele-medicine, military, tamper detection, and many more. This paper represents the robust watermarking approach using Paillier homomorphic cryptosystem with Arnold transformation. In this, the watermarking system is primarily prepared at an encrypted DWT-DCT domain. Cryptosystem is exploited at this time to encrypt the original media. For more security of multimedia content, the watermark image is scrambled through Arnold scrambling technique. The embedding process is done here to produce the encrypted watermark image followed by the encryption process. At recovery phase, decryption of encrypted watermark image to get the original and watermark image is done. The experimental result has shown that watermarking method is more robust and offers the security of digital media.

Secure Multiparty Equality Check Based on Homomorphic Cryptosystem

There exist many scenarios where multiple parties jointly work on some common project but these parties are not interested to show actual value of data to each other. Here we propose an algorithm where multiple cooperating but distrustful parties can compare their data for equality without disclosing it to one another. This is an improvement over two party comparison algorithm devised earlier by other researchers. The proposed work is suitable for semi honest adversaries who respect rules of the protocol but somehow try to know private values with other parties.