• The Journal of Korean Institute of Communications and Information Sciences
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• v.35 no.5C
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• pp.445-453
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• 2010

Because of heavy computational overheads, the use of public key cryptosystem in Wireless Sensor Networks seems unfeasible. But some recent researches show that certain public key cryptosystem can be used in WSN, in which the key and data size, power consumption is relatively small. The NTRU cryptosystem is suggested as one of the candidates of public key cryptosystems which can be used in wireless sensor networks. In this paper, we propose an efficient key agreement scheme using NTRU and we show that it can be used in wireless sensor networks.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.15 no.2
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• pp.95-103
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• 2005

Convolution modular lattices appeared in the analysis of NTRU public key cryptosystem. We present three guess-then-reduce methods on convolution modular lattices, and apply them to practical parameters of NTRU. For the present our methods don't affect significantly the security of them. However, Hey have room for improvement and can be used to estimate mole closely the security of systems related to convolution modular lattices.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.28 no.3
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• pp.551-561
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• 2018

As the computational technology using quantum computing has been developed, several threats on cryptographic systems are recently increasing. Therefore, many researches on post-quantum cryptosystems which can withstand the analysis attacks using quantum computers are actively underway. Nevertheless, the lattice-based NTRU system, one of the post-quantum cryptosystems, is pointed out that it may be vulnerable to the fault injection attack which uses the weakness of implementation of NTRU. In this paper, we investigate the fault injection attacks and their previous countermeasures on the NTRU signature system and propose a secure and efficient countermeasure to defeat it. As a simulation result, the proposed countermeasure has high fault detection ratio and low implementation costs.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1094-1107
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• 2013

NTRU cryptosystem has been suggested for protecting wireless body area networks, which is secure in the sense of traditional cryptanalysis. In this paper, we fulfill the first power analysis attack on the ultra-low-power environment of wireless body area networks. Specifically, two practical differential power analyses on NTRU algorithm are proposed, which can attack the existing countermeasures of NTRU. Accordingly, we suggest three countermeasures against our attacks. Meanwhile, practical experiments show that although the attacks in this paper are efficient, our countermeasures can resist them effectively.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.19 no.2
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• pp.11-21
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• 2009

The NTRU cryptosystem proposed by Hoffstein et al. in 1990s is a public key cryptosystem based on hard lattice problems. NTRU has many advantages compared to other public key cryptosystems such as RSA and elliptic curve cryptosystems. For example, it guarantees high speed encryption and decryption with the same level of security, and there is no known quantum computing algorithm for speeding up attacks against NTRD. In this paper, we analyze the security of NTRU against the simple power analysis (SPA) attack and the statistical power analysis (STPA) attack such as the correlation power analysis (CPA) attack First, we implement NTRU operations using NesC on a Telos mote, and we show how to apply CPA to recover a private key from collected power traces. We also suggest countermeasures against these attacks. In order to prevent SPA, we propose to use a nonzero value to initialize the array which will store the result of a convolution operation. On the other hand, in order to prevent STPA, we propose two techniques to randomize power traces related to the same input. The first one is random ordering of the computation sequences in a convolution operation and the other is data randomization in convolution operation.

• 한국IT서비스학회:학술대회논문집
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• 2009.05a
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• pp.205-208
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• 2009

이 논문에서는 RFID(Radio Frequency IDentification)에 대한 여러 가지 보안위협에 대하여 간단히 알아보고 그에 대응하는 안전한 암호학적 도구(Primitive)에 대하여 알아보겠다. 공개키 암호시스템(PKC, Public Key Cryptosystem)에 사용되는 타원곡선(EC, Elliptic Curve) 암호, NTRU(N-th degree TRUncated polynomial ring) 암호, Rabin 암호 등은 초경량 하드웨어 구현에 적합한 차세대 암호시스템으로서 안전한 RFID 인증서비스 제공과 프라이버시보호를 가능케 한다. 특히, 본고에서는 초경량 키의 길이, 저전력 소모성, 고속구현 속도를 갖는 타원곡선암호의 안전성에 대한 가이드라인을 제공하겠다.

• Journal of Korea Multimedia Society
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• v.20 no.11
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• pp.1768-1775
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• 2017

The SIP(Session Initiation Protocol) is an application layer call signaling protocol which can create, modify and terminate the session of user, and provides various services in combination with numerous existing protocols. However, most of cryptosystems for SIP cannot prevent quantum computing attack because they have used ECC(Elliptic Curve Cryptosystem). In this paper, we propose a NTRU based authentication and key distribution protocol for SIP in order to protect quantum computing attacks. The proposed protocol can prevent various attacks such as quantum computing attack, server spoofing attack, man-in-the middle attack and impersonation attack anonymity, and our protocol can provide user's anonymity.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.27 no.3
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• pp.439-448
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• 2017

It is news from nowhere that post-quantum cryptography has side-channel analysis vulnerability. Side-channel analysis attack method and countermeasures for code-based McEliece cryptosystem and lattice-based NTRU cryptosystem have been investigated. Unfortunately, the investigation of the ring-LWE cryptosystem in terms of side-channel analysis is as yet insufficient. In this paper, we propose a chosen ciphertext simple power analysis attack that can be applied when ring-LWE cryptography operates on 8-bit devices. Our proposed attack can recover the key only with [$log_2q$] traces. q is a parameter related to the security level. It is used 7681 and 12289 to match the common 128 and 256-bit security levels, respectively. We identify the vulnerability through experiment that can reveal the secret key in modular add while the ring-LWE decryption performed on real 8-bit devices. We also discuss the attack that uses a similarity measurement method for two vectors to reduce attack time.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.31 no.3
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• pp.481-496
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• 2021

It is imperative to migrate the current public key cryptosystem to a quantum-resistance system ahead of the realization of large-scale quantum computing technology. The National Institute of Standards and Technology, NIST, is promoting a public standardization project for Post-Quantum Cryptography(PQC) and also many research efforts have been conducted to apply PQC to TLS(Transport Layer Security) protocols, which are used for Internet communication security. In this paper, we propose a scenario in which a server and multi-clients share session keys on TLS by using the parallelized NTRU which is PQC in the key exchange process. In addition, we propose a method of accelerating NTRU using GPU and analyze its efficiency in an environment where a server needs to process large-scale data simultaneously.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.12 no.3
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• pp.49-59
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• 2002

As the electronic commerce increases rapidly in the mobile communication, security issues become more important. A suitable authentication and key agreement for the mobile communication environment is a essential condition. Some protocols based on the public key cryptosystem such as Diffie-Hellman, EIGamal etc. were adapted in the mobile communication. But these protocols that are based on the difficult mathematical problem in the algebra, are so slow and have long key-length. Therefore, these have many limitation to apply to the mobile communication. In this paper, we propose an authentication and key agreement protocol based on NTRU to overcome the restriction of the mobile communication environment such as limited sources. low computational fewer, and narrow bandwidth. The proposed protocol is faster than other protocols based on ECC, because of addition and shift operation with small numbers in the truncated polynomial ring. And it is as secure as other existent mathematical problem because it is based on finding the Shortest or Closest Vector Problem(SVP/CVP).