While recent timed-release encryption (TRE) schemes are implicitly supported by a certificateless encryption (CLE) mechanism, the security models of CLE and TRE differ and there is no generic transformation from a CLE to a TRE. This paper gives a generalized model for CLE that fulfills the requirements of TRE. This model is secure against adversaries with adaptive trapdoor extraction capabiliti...

A public key encryption with keyword search (PEKS) scheme does not allow the user to decrypt the encrypted keyword or decrypt the encrypted massage. This "no-decryption" property also limits the applicability of a PEKS scheme. Fuhr and Paillier also left an open problem on how to come up with a decryptable PEKS which security does not rely on random oracles. In this paper, we first enhance the ...

We propose distributed decryption schemes for somewhat homomorphic encryption (SHE). The proposed schemes are constructed based on the encryption scheme by Brakerski and Vaikuntanathan. In SHE, homomorphic multiplication increases the number of elements in a ciphertext. The proposed scheme can decrypt a ciphertext containing more than two elements with k out of N parties. The distributed decryp...

We show that an encryption scheme cannot have a simple decryption function and be homomorphic at the same time, even with added noise. Specifically, if a scheme can homomorphically evaluate the majority function, then its decryption cannot be weakly-learnable (in particular, linear), even if the probability of decryption error is high. (In contrast, without homomorphism, such schemes do exist a...

In the present scenario, no technology that's connected to internet is unhackable. All digital services like communication, military and medical imaging systems, multimedia systems require reliable security in storage transmission of images. The importance protecting images cannot be overstated. Therefore, there a need for image encryption techniques order hide from such attacks. this process, ...

In their 1993 paper, “Statistical Techniques for Language Recognition: An Introduction and Guide for Cryptanalysts,” Ganesan and Sherman present several statistical formulae useful for language recognition based on using a finite stationary Markov as a model to represent language. In my project, I verify the effectiveness of two of these formulae by examining the results when they are applied t...

In this paper, we propose an efficient protocol for proving the correctness of shuffling and an efficient protocol for simultaneously proving the correctness of both shuffling and decryption. The former protocol is the most efficient in computational and communication complexity among 3-move honest verifier perfect zero-knowledge protocols for proving a shuffling of ElGamal cipher-texts. The la...