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Chapter and Conference Paper
A Novel Scheme of Schnorr Multi-signatures for Multiple Messages with Key Aggregation
A digital signature is essential in verifying the reliability of people and data over networks, such as through web server certificates, authentication, and blockchain technologies. In blockchain, multi-signat...
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Chapter and Conference Paper
Block Cipher Modes of Operation for Heterogeneous Format Preserving Encryption
Format-preserving encryption (FPE), a kind of symmetric encryption, has caught a great deal of attention of late years. FPE, as the name suggests, does not change the format of inputs which may include the len...
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Chapter and Conference Paper
Recovering Attacks Against Linear Sketch in Fuzzy Signature Schemes of ACNS 2015 and 2016
In biometrics, template protection aims to protect the confidentiality of templates (i.e., enrolled biometric data) by certain conversion. At ACNS 2015, as a new approach of template protection, Takahashi et a...
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Article
Computational hardness of IFP and ECDLP
The RSA cryptosystem and elliptic curve cryptography (ECC) have been used practically and widely in public key cryptography. The security of RSA and ECC respectively relies on the computational hardness of the...
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Chapter and Conference Paper
Privacy-Preserving Fuzzy Commitment for Biometrics via Layered Error-Correcting Codes
With the widespread development of biometrics, concerns about security and privacy are increasing. In biometrics, template protection technology aims to protect the confidentiality of biometric templates (i.e....
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Chapter and Conference Paper
Secure Statistical Analysis Using RLWE-Based Homomorphic Encryption
Homomorphic encryption enables various calculations while preserving the data confidentiality. Here we apply the homomorphic encryption scheme proposed by Brakerski and Vaikuntanathan (CRYPTO 2011) to secure s...
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Article
Open AccessSecret computation of purchase history data using somewhat homomorphic encryption
We consider secret computation of purchase history data among two companies of different type of business in order to identify purchase patterns without revealing customer information of each company. Among se...
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Chapter and Conference Paper
Practical Packing Method in Somewhat Homomorphic Encryption
Somewhat homomorphic encryption is public key encryption supporting a limited number of both additions and multiplications on encrypted data, which is useful for performing fundamental computations with protec...
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Chapter and Conference Paper
Privacy-Preserving Wildcards Pattern Matching Using Symmetric Somewhat Homomorphic Encryption
The basic pattern matching problem is to find the locations where a pattern occurs in a text. We give several computations enabling a client to obtain matching results from a database so that the database can ...
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Chapter and Conference Paper
Packed Homomorphic Encryption Based on Ideal Lattices and Its Application to Biometrics
Among many approaches for privacy-preserving biometric authentication, we focus on the approach with homomorphic encryption, which is public key encryption supporting some operations on encrypted data. In biom...
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Chapter and Conference Paper
Analysis of Lattice Reduction Attack against the Somewhat Homomorphic Encryption Based on Ideal Lattices
In 2009, Gentry first proposed a concrete method for constructing a fully homomorphic encryption (FHE) scheme, which supports arbitrary operations on encrypted data. The construction of the FHE scheme starts f...
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Chapter and Conference Paper
Preimage Attacks on Full-ARIRANG: Analysis of DM-Mode with Middle Feed-Forward
In this paper, we present preimage attacks on hash function ARIRANG, which is one of the first round candidates in the SHA-3 competition. Although ARIRANG was not chosen for the second round, the vulnerability...
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Chapter and Conference Paper
Breaking Pairing-Based Cryptosystems Using η T Pairing over GF(397)
In this paper, we discuss solving the DLP over GF(36·97) by using the function field sieve (FFS) for breaking paring-based cryptosystems using the η T pairing o...
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Chapter and Conference Paper
Key Length Estimation of Pairing-Based Cryptosystems Using η T Pairing
The security of pairing-based cryptosystems depends on the difficulty of the discrete logarithm problem (DLP) over certain types of finite fields. One of the most efficient algorithms for computing a pairing i...
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Chapter and Conference Paper
On the Strength Comparison of the ECDLP and the IFP
At present, the RSA cryptosystem is most widely used in public key cryptography. On the other hand, elliptic curve cryptography (ECC) has recently received much attention since smaller ECC key sizes provide th...
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Chapter and Conference Paper
Preimage Attacks on Full-ARIRANG (Poster)
This paper presents ongoing work toward the first preimage attacks on hash function ARIRANG, which is one of the first round candidates in the SHA-3 competition. ARIRANG has an unique design where the feed-for...
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Chapter and Conference Paper
Preimage Attacks on Step-Reduced RIPEMD-128 and RIPEMD-160
This paper presents the first results on the preimage resistance of ISO standard hash functions RIPEMD-128 and RIPEMD-160. They were designed as strengthened versions of RIPEMD. While preimage attacks on the f...
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Chapter and Conference Paper
Matrix Representation of Conditions for the Collision Attack of SHA-1 and Its Application to the Message Modification
In this paper, we propose a matrix representation of Chaining Variable Condition (CVC) and Message Condition (MC) for the collision attack on the hash function SHA-1. Then we apply this to an algorithm for con...
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Chapter and Conference Paper
Timing to Block Scanning Malwares by Using Combinatorics Proliferation Model
One of the worst threats present in an enterprise network is the propagation of “scanning malware” (e.g., scanning worms and bots). It is important to prevent such scanning malware from spreading within an ent...
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Article
Low-density attack revisited
The low-density attack proposed by Lagarias and Odlyzko is a powerful algorithm against the subset sum problem. The improvement algorithm due to Coster et al. would solve almost all the problems of density <0....
