Dowon Hong

An efficient key distribution scheme with self-healing property

The main property of the self-healing key distribution scheme is that users are capable of recovering lost group keys on their own, without requesting additional transmission from the group manager. In this paper, we propose a new self-healing key distribution scheme, which is optimal in terms of user memory storage and more efficient in terms of communication complexity than the previous results.

Identity-based proxy signature from lattices

Most of the provably-secure proxy signature schemes rely on the average-case hardness problems such as the integer factorization problems and the discrete logarithm problems. Therefore, those schemes are insecure to quantum analysis algorithms, since there exist quantum algorithms efficiently solving the factorization and logarithm problems. To make secure proxy signature schemes against quantum analysis, some lattice-based proxy signature schemes are suggested. However, none of the suggested lattice-based proxy signature schemes is proxy-protected in the adaptive security model. In the paper, we propose a provably-secure ID-based proxy signature scheme based on the lattice problems. Our scheme is proxy-protected in the adaptive security model.

New efficient bit-parallel polynomial basis multiplier for special pentanomials

We present a bit-parallel polynomial basis multiplier based on a new divide-and-conquer approach using squaring. In particular, we apply the proposed approach to special types of irreducible pentanomials called as types I and II pentanomials, and induce explicit formulae and complexities of the proposed multiplier for these types of pentanomials. As a result, the proposed multiplier for type I pentanomials has almost the same time complexity, but about 25% reduced space complexity compared with the best known results in the literature. For type II pentanomials, we obtain the multiplier which has the lowest time complexity and about 25% reduced space complexity than the best known polynomial basis multipliers.

Signcryption with fast online signing and short signcryptext for secure and private mobile communication

Signcryption scheme is one of the useful tools for secure communication where authenticity and confidentiality are simultaneously required. Now, mobile devices are more and more widely used for communication, and thus it is desirable to design a scheme suitable to mobile applications. In this paper, we propose a signcryption scheme which is efficient enough to be implemented on mobile devices. In our scheme, we need only one multiplication in an online phase, and thus a signcryptor can generate a signcryptext very efficiently in the online phase. Moreover, the size of signcryptext is very short compared with exsiting schemes, and thus our scheme is very efficient in terms of communication overhead. The security of our signcryption scheme is proven in the random oracle model.

Comments on “Multiway Splitting Method for Toeplitz Matrix Vector Product”

We propose block decompositions for the Toeplitz matrix-vector product (TMVP) using the k-way splitting method presented in the above paper. As a result, we show that the space complexity for TMVP can be improved.

New Block Recombination for Subquadratic Space Complexity Polynomial Multiplication Based on Overlap-Free Approach

In this paper, we present new parallel polynomial multiplication formulas which result in subquadratic space complexity. The schemes are based on a recently proposed block recombination of polynomial multiplication formula. The proposed two-way, three-way, and four-way split polynomial multiplication formulas achieve the smallest space complexities. Moreover, by providing area-time tradeoff method, the proposed formulas enable one to choose a parallel formula for polynomial multiplication which is suited for a design environment.

Comments on “On the Polynomial Multiplication in Chebyshev Form”

In the above paper, Akleylek proposed an efficient multiplication algorithm for polynomials in Chebyshev form. In this comment, we show that a recombination of the above proposed algorithm induces more efficient algorithm for the multiplications of polynomials in Chebyshev form.

A Strong Binding Encryption Scheme from Lattices for Secret Broadcast

In 2009, Jeong et al. suggested a secret broadcast scheme in broadcasting networks using binding encryption. With a binding encryption scheme, a ciphertext is made for a group of receivers, and we can assure that all of the receivers will extract the exact same plaintext from the ciphertext. However, Wu et al. pointed out that Jeong et al.s binding encryption scheme provides only weak decryption consistency. In this paper, we suggest a binding encryption scheme that provides strong decryption consistency without random oracles. Our binding encryption scheme uses the unique properties of lattices to provide strong decryption consistency.

Efficient multiplier based on hybrid approach for Toeplitz matrix-vector product ☆

Abstract We propose a hybrid approach for a Toeplitz matrix–vector product (TMVP) of size k ⋅ 2 i 3 j , where k ≥ 1 and i , j ≥ 0 . It is possible to make trade-offs between time and space complexities for a TMVP by choosing values k, i, and j properly. We show that the multiplier based on the proposed hybrid TMVP approach has lower space as well as time complexities than other subquadratic space complexity multipliers for five fields recommended by NIST. Moreover, for those five fields, the space complexities of the proposed multiplier are reduced by a minimum 59 % and a maximum 77 % compared with quadratic space complexity multiplier.

Explicit formulae for Mastrovito matrix and its corresponding Toeplitz matrix for all irreducible pentanomials using shifted polynomial basis

We propose explicit formulae of the Mastrovito matrix M and its corresponding Toeplitz matrix T for an arbitrary irreducible pentanomial using shifted polynomial basis. We also give the complexity of the Toeplitz matrix for a pentanomial. This yields the complexity of a multiplier based on Toeplitz matrix-vector product (TMVP) for an arbitrary irreducible pentanomial for the first time. Moreover, we introduce a new type of pentanomials for which a multiplier based on TMVP is efficiently implemented. We show that the complexity of a subquadratic space complexity multiplier for such a special type of pentanomials is comparable with that for trinomials. HighlightsWe propose explicit formulae of the Mastrovito matrix for a pentanomial.We propose explicit formulae of the Toeplitz matrix for a pentanomial.We give the complexity of the Toeplitz matrix for a pentanomial.We give the complexity of a multiplier based on TMVP for a pentanomial.We give conditions on pentanomials for an efficient multiplier based on the TMVP.