The content distributors take content protection and Digital Rights Management of content very serious. As such many provisions already exist to make sure content is securely sent to, and only to, licensed clients. In this paper an alternative content encryption system is proposed by using the homomorphic features of asymmetric cryptography systems. Using a split-key derivative of the RSA crypt...

We present a new cryptosystem based on ideal arithmetic in quadratic orders. The method of our trapdoor is diierent from the Diie-Hellman key distribution scheme or the RSA cryp-tosystem. The plaintext m is encrypted by mp r , where p is a xed element and r is a random integer, so our proposed cryptosystem is a probabilistic encryption scheme and has the ho-momorphy property. The most prominent...

Key agreement protocols are essential for secure communications in open and distributed environments. Recently identity-based key agreement protocols have been increasingly researched because of the simplicity of a public key management. The basic idea behind an identity-based cryptosystem is that a public key is the identity (an arbitrary string) of a user, and the corresponding private key is...

It is striking to observe that two decades after the discovery of public-key cryptography, the cryptographer’s toolbox contains only a dozen of asymmetric encryption schemes. This rarity and the fact that today’s most popular schemes had so far defied all complexity classification a.ttempts strongly motivates the design of new asymmetric cryptosystems. Interestingly, the crypt,ographic communit...

We discuss a matrix public key cryptosystem and its numerical implementation.

We describe a public-key cryptosystem with worst-case/average case equivalence. The cryptosystem has an amortized plaintext to ciphertext expansion of O(n), relies on the hardness of the Õ(n)-unique shortest vector problem for lattices, and requires a public key of size at most O(n) bits. The new cryptosystem generalizes a conceptually simple modification of the “Ajtai-Dwork” cryptosystem. We p...

We present a cryptosystem which is complete for the class of probabilistic public-key cryptosystems with bounded error. Besides traditional encryption schemes such as RSA and El Gamal, this class contains probabilistic encryption of Goldwasser-Micali as well as Ajtai-Dwork and NTRU cryptosystems. The latter two are known to make errors with some small positive probability. To our best knowledge...

In this paper, the authors give the definitions of a coprime sequence and a lever function, and describe the five algorithms and six characteristics of a prototypal public key cryptosystem which is used for encryption and signature, and based on three new problems and one existent problem: the multivariate permutation problem (MPP), the anomalous subset product problem (ASPP), the transcendenta...

We propose a lattice-based cryptosystem by modifying the Regev’05 cryptosystem (STOC 2005), and design a proof of secret-key knowledge. Lattice-based public-key identification schemes have already been proposed, however, it is unknown that their public keys can be used for the public keys of encryption schemes. Our modification admits the proof of knowledge on its secret key, however, we need a...

XTR is one of the most efficient public-key cryptosystems that allow us to compress the communication bandwidth of their ciphertext. The compact representation can be achieved by deploying a subgroup Fq2 of extension field Fq6 , so that the compression ratio of XTR cryptosystem is 1/3. On the other hand, Dijk et al. proposed an efficient public-key cryptosystem using a torus over Fq30 whose com...