• KIPS Transactions on Computer and Communication Systems
• /
• v.11 no.12
• /
• pp.453-460
• /
• 2022

As high-performance quantum computers are expected to be developed, studies are being actively conducted to build a post-quantum security system that is safe from potential quantum computer attacks. When the Grover's algorithm, a representative quantum algorithm, is used to search for a secret key in a symmetric key cryptography, there may be a safety problem in that the security strength of the cipher is reduced to the square root. NIST presents the post-quantum security strength estimated based on the cost of the Grover's algorithm required for an attack of the cryptographic algorithm as a post-quantum security requirement for symmetric key cryptography. The estimated cost of Grover's algorithm for the attack of symmetric key cryptography is determined by the quantum circuit complexity of the corresponding encryption algorithm. In this paper, the quantum circuit of the SCHWAEMM algorithm, AEAD family of SPARKLE, which was a finalist in NIST's lightweight cryptography competition, is efficiently implemented, and the quantum cost to apply the Grover's algorithm is analyzed. At this time, the cost according to the CDKM ripple-carry adder and the unbounded Fan-Out adder is compared together. Finally, we evaluate the post-quantum security strength of the lightweight cryptography SPARKLE SCHWAEMM algorithm based on the analyzed cost and NIST's post-quantum security requirements. A quantum programming tool, ProjectQ, is used to implement the quantum circuit and analyze its cost.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.14 no.3
• /
• pp.1439-1444
• /
• 2013

Recently, as the use of the applications like online banking and stock trading is increasing by the rapid development of the network, security of data content is becoming more and more important. Accordingly, public key or symmetric key encryption algorithm is widely used in open networks such as the internet for the protection of data. Generally, public key cryptographic systems is based on two famous number theoretic problems namely factoring or discrete logarithm problem. So, public key cryptographic systems is relatively slow compared to symmetric key cryptography systems. Among public key cryptographic systems, the advantage of ECC compared to RSA is that it offers equal security for a far smaller key. For this reason, ECC is faster than RSA. In this paper, we propose a efficient key generation method for elliptic curve cryptography system based on the real number field.

• Journal of Information Technology Services
• /
• v.3 no.2
• /
• pp.119-127
• /
• 2004

A mobile ad hoc network(MANET) is a network where a set of mobile devices communicate among themselves using wireless transmission without the support of a fixed network infrastructure. The use of wireless links makes MANET susceptible to attack. Eavesdroppers can access secret information, violating network confidentiality, and compromised nodes can launch attack from within a network. Therefore, the security for MANET depends on using the cryptographic key, which can make the network reliable. In addition, because MANET has a lot of mobile devices, the authentication scheme utilizing only the symmetric key cryptography can not support a wide range of device authentication. Thereby, PKI based device authentication technique in the Ad Hoc network is essential and the paper will utilize the concept of PKI. Especially, this paper is focused on the key management technique of PKI technologies that can offer the advantage of the key distribution, authentication, and non-reputation, and the issuing and managing technique of certificates based on clustering using Threshold Cryptography for secure communication in MANET.

• Journal of information and communication convergence engineering
• /
• v.9 no.6
• /
• pp.683-688
• /
• 2011

The wireless sensor network (WSN) is well known for an enabling technology for the ubiquitous environment such as real-time surveillance system, habitat monitoring, home automation and healthcare applications. However, the WSN featuring wireless communication through air, a resource constraints device and irregular network topology, is threatened by malicious nodes such as eavesdropping, forgery, illegal modification or denial of services. For this reason, security in the WSN is key factor for utilizing the sensor network into the commercial way. There is a series of symmetric cryptography proposed by laboratory or industry for a long time. Among of them, recently proposed HUMMINGBIRD algorithm, motivated by the design of the well-known Enigma machine, is much more suitable to resource constrained devices, including smart card, sensor node and RFID tags in terms of computational complexity and block size. It also provides resistance to the most common attacks such as linear and differential cryptanalysis. In this paper, we implements ultra-lightweight cryptography, HUMMINGBIRD algorithm into the resource constrained device, sensor node as a perfectly customized design of sensor node.

• Journal of information and communication convergence engineering
• /
• v.14 no.4
• /
• pp.233-239
• /
• 2016

A remote control system (RCS) can monitor a user's confidential information by using the broadcast receivers in Android OS. However, the current RCS detection methods are based only on a virus vaccine. Therefore, if the user's smartphone is infected by a brand new RCS, these methods cannot detect this new RCS immediately. In this paper, we present a secure message transmission medium. This medium is completely isolated from networks and can communicate securely through a QR code channel by using symmetric key cryptography such as the AES block cipher and public key cryptography such as elliptic curve cryptography for providing security. Therefore, the RCS cannot detect any confidential information. This approach is completely immune to any RCS attacks. Furthermore, we present a secure QR code-based key exchange protocol by using the elliptic curve Diffie-Hellman method and message transmission protocols; the proposed protocol has high usability and is very secure.

• ETRI Journal
• /
• v.43 no.6
• /
• pp.1113-1129
• /
• 2021

Lightweight ciphers are increasingly employed in cryptography because of the high demand for secure data transmission in wireless sensor network, embedded devices, and Internet of Things. The PRESENT algorithm as an ultralightweight block cipher provides better solution for secure hardware cryptography with low power consumption and minimum resource. This study generates the key using key rotation and substitution method, which contains key rotation, key switching, and binary-coded decimal-based key generation used in image encryption. The key rotation and substitution-based PRESENT architecture is proposed to increase security level for data stream and randomness in cipher through providing high resistance to attacks. Lookup table is used to design the key scheduling module, thus reducing the area of architecture. Field-programmable gate array (FPGA) performances are evaluated for the proposed and conventional methods. In Virtex 6 device, the proposed key rotation and substitution PRESENT architecture occupied 72 lookup tables, 65 flip flops, and 35 slices which are comparably less to the existing architecture.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.26 no.6
• /
• pp.1413-1419
• /
• 2016

In these days, there are a lot of research results on the Post-Quantum Cryptography according to developing of quantum computing technologies and the announcement of the NIST's Post-Quantum Cryptography standard project. The key size of the existing symmetric key block ciphers are needed to increase and the security of discrete logarithm based public key cryptography can be broken by Grover's algorithm and Shor's algorithm. By this reason, a lot of cryptologist and mathematician research on safe cryptography against the quantum computer which is called as the Post-Quantum Cryptography. In this paper, we survey on recent technical trend on the Hash-Based Signature Scheme which is one of the Post-Quantum Cryptography and suggest the prospect of the Hash-Based Signature Scheme.

• The Journal of the Korea institute of electronic communication sciences
• /
• v.17 no.2
• /
• pp.357-364
• /
• 2022

A pseudo-random number generator (PRNG) is a program used when a large amount of random numbers is needed. It is used to generate symmetric keys in symmetric key cryptography systems, generate public key pairs in public key cryptography or digital signatures, and generate columns used for padding with disposable pads. Cellular Automata (CA), which is useful for specific representing nonlinear dynamics in various scientific fields, is a discrete and abstract computational system that can be implemented in hardware and is applied as a PRNG that generates keys in cryptographic systems. In this paper, I propose an algorithm for synthesizing a programmable 5-neighbor CA based PRNG that can effectively generate a nonlinear sequence using 5-neighbor CA with the radius of the neighboring cell increased by 2.

• Smart Media Journal
• /
• v.12 no.2
• /
• pp.76-82
• /
• 2023

In the 4th industrial revolution, the blockchain that distributes and manages data through a P2P network is used as a new decentralized networking paradigm in various fields such as manufacturing, culture, and public service. However, with the advent of quantum computers, quantum algorithms that are able to break existing cryptosystems such as hash function, symmetric key, and public key cryptography have been introduced. Currently, because most major blockchain systems use an elliptic curve cryptography to generate signatures for transactions, they are insecure against the quantum adversary. For this reason, the research on the quantum-resistant blockchain that utilizes lattice-based cryptography for transaction signatures is needed. Therefore, in this paper, we propose a blind signature scheme for the blockchain in which the contents of the signature can be verified later, as well as signing by hiding the contents to be signed using lattice-based cryptography with the property of quantum resistance. In addition, we prove the security of the proposed scheme using a random oracle model.

• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.3
• /
• pp.323-330
• /
• 2021

Recently, the advantages of high-speed arithmetic in quantum computers have been known, and interest in quantum circuits utilizing qubits has increased. The Grover algorithm is a quantum algorithm that can reduce n-bit security level symmetric key cryptography and hash functions to n/2-bit security level. Since the Grover algorithm work on quantum computers, the symmetric cryptographic technique and hash function to be applied must be implemented in a quantum circuit. This is the motivation for these studies, and recently, research on implementing symmetric cryptographic technique and hash functions in quantum circuits has been actively conducted. However, at present, in a situation where the number of qubits is limited, we are interested in implementing with the minimum number of qubits and aim for efficient implementation. In this paper, the domestic hash function LSH is efficiently implemented using qubits recycling and pre-computation. Also, major operations such as Mix and Final were efficiently implemented as quantum circuits using ProjectQ, a quantum programming tool provided by IBM, and the quantum resources required for this were evaluated.