Earticle

Credential Stuffing 공격의 2단계 인증에 사용되는 TOTP(Time based One Time Password)는 일회성 비밀번호(OTP)를 시간 기반으로 생성하는 간편하고 널리 사용되는 인증 방식이지만, 유효 시간 내 동일 OTP를 재사용할 수 있어 재사용 공격에 취약하다는 한계가 있다. 따라서 본 논문에서는 이러한 보안 취약점을 보완하기 위해 경량 자료 구조인 Counting Bloom Filter(CBF)를 결합하여 OTP 사용 이력을 추적하여 재사용 여부를 효 율적으로 검출할 수 있는 방법을 제안하였다. 결론적으로 제안한 CBF+TOTP 방식은 기존 TOTP의 재사용 공격 과 같은 보안 취약점을 보완하면서도 경량성과 확장성을 유지할 수 있는 효과적인 인증 기법이다.

Credential stuffing attacks exploit reused or compromised credentials to gain unauthorized access to user accounts. As a countermeasure, Time-Based One-Time Passwords (TOTP) are widely used in two-factor authentication (2FA) systems. However, TOTP remains vulnerable to replay attacks, as the same OTP can be reused within its valid time window. To address this limitation, we propose an enhanced authentication method that combines TOTP with a Counting Bloom Filter (CBF), a lightweight and space-efficient data structure. By recording hashed OTPs in the CBF, the system can efficiently detect and prevent OTP reuse without the need for persistent storage. In conclusion, the proposed CBF+TOTP scheme effectively addresses security vulnerabilities of traditional TOTP, such as susceptibility to replay attacks, while maintaining lightweight operation and scalability.

Recently, a fast and secure hash function SFHA - 256 has been proposed and claimed as more secure and as having a better performance than the SHA - 256. In this paper an improved version of SFHA - 256 is proposed and analyzed using two parameters, namely the avalanche effect and uniform deviation. The experimental results and further analysis ensures the performance of the newly proposed and improved SFHA-256. From the analysis it can be concluded that the newly proposed algorithm is more secure, efficient, and practical.

본 논문은 병렬 해쉬 결합 연산에서 데이터 분산 시에 나타나는 부하의 불균형과 버켓 오버플로우를 해결하기 위한 새로운 데이터 분산 방법을 제안한다. 제안된 데이터 분산 방법은 편재된 분포를 갖는 데이터들을 히스토프로그램 변환 기법에 의하여 각 노드의 성능에 따라 균일하게 분산 시킨다. 또한 본 논문에서는 이 분산 방법을 병렬 해쉬 결합 연산에 적용하여 데이터 편재에 따른 성능 저하를 해결할 수 있는 알고리즘을 제안하고, 기존의 병렬 결합 알고리즘들과의 성능 비교를 위하여 모의 실험결과COREDB 병렬 데이터베이스 컴퓨터 상에서의 실험을 통하여 편재된 분포를 갖는 데이터에 대하여 성능 분석을 수행한다. 실험 결과에서 편재된 데이터에 대하여 기존의 다른 결합 연산 알고리즘보다 제안된 알고리즘이 우수한 성능을 나타냄을 보인다.

In this pater, we first propose a data distribution framework to resolve load imbalance and bucket oerflow in parallel hash join.Using the histogram equalization technique, the framework transforms a histogram of skewed data to the desired uniform distribution that corresponds to the relative computing power of node processors in the system.Next we propose an effcient parallel hash join algorithm for handing skwed data based on the proposed data distribution methodology.For performance comparison of our algorithm with other hash join algorithms.we perform similation experiments and actual exeution on COREDB database computer with 8-node hyperube architecture. In these experiments, skwed data distebution of the join atteibute is modeled using a Zipf-like distribution.The perfomance studies undicate that our algorithm outperforms other algorithms in the skewed cases.

최근에는 양자 컴퓨터의 빠른 연산의 장점이 알려지면서 큐비트를 활용한 양자회로에 대한 관심이 높아지고 있다. 그루버 알고리즘은 n-bit의 보안 레벨의 대칭키 암호와 해시 함수를 n/2-bit 보안 레벨까지 낮출 수 있는 양자 알고리즘이다. 그루버 알고리즘은 양자 컴퓨터상에서 동작하기 때문에 적용 대상이 되는 대칭키 암호와 해시함수는 양자 회로로 구현되어야 한다. 이러한 연구 동기로, 최근 들어 대칭키 암호 또는 해시 함수를 양자 회로로 구현하는 연구들이 활발히 수행되고 있다. 하지만 현재는 큐비트의 수가 제한적인 상황으로 최소한의 큐비트 개수로 구현하는 것에 관심을 가지고 효율적인 구현을 목표로 하고 있다. 본 논문에서는 국산 해시함수 LSH 구현에 큐빗 재활용, 사전 연산을 통해 사용 큐빗 수를 줄였다. 또한, Mix, Final 함수와 같은 핵심 연산들을 IBM에서 제공하는 양자 프로그래밍 툴인 ProjectQ를 사용하여 양자회로로 효율적으로 구현하였고 이에 필요한 양자 자원들을 평가하였다.

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.

기존 웹 페이지는 사용자가 해당 페이지를 요청할 때 마다 새로운 페이지를 다운로드 받아 사용자에게 제공하였다. 따라서 동일한 페이지를사용자가 반복해서 요청할 경우 동일한 리소스에 대한 다운로드만을 반복하게 된다. 이는 불필요한 데이터의 소비를 발생시키는 요인이다. 본 논문에서는 사용자와 서버간의 불필요한 요청에 의해 발생하는 데이터의 소모를 감소시키고, 콘텐츠 제공 속도를 향상시키는 대에 초점을 맞추었다. 따라서 이를 방지하기 위하여 본 논문에서는 캐싱 시스템과 사용자가 요청하는 파일의 변경을 감지할 수있는 해시 함수를 이용한 해시 값의 비교를 통해 항상 최신 캐시를 유지하면서 데이터 소모를 줄일 수 있는 알고리즘에 대하여 논하고, 웹 콘텐츠의 속도 향상을 위한 서비스 워커 기반의 캐싱 시스템을 설계하고 성능을 평가하였다.

The existing web page was downloaded and provided to the user every time the user requested the page. Therefore, if the same page is repeatedly requested by the user, only the download for the same resource is repeated. This is a factor that causes unnecessary consumption of data. We focus on reducing data consumption caused by unnecessary requests between users and servers, and improving content delivery speed. Therefore, in this paper, we propose a caching system and an algorithm that can reduce the data consumption while maintaining the latest cache by comparing the hash value using the hash function that can detect the change of the file requested by the user.

최근 소셜 네트워크 서비스가 폭발적으로 증가하면서 빅데이터 분석 연구가 많이 진행되고 있 다. 이 중, 해쉬함수를 이용해서 빅데이터를 분석하는데 주로 이용되는 최소 완전 해쉬함수(MPHF) 방법은 이론적으로는 해쉬충돌이 일어나지 않지만 실제로 사용하면 잦은 충돌 문제가 발생한다. 이로 인해서 빅데이터 분석시간이 길어진다. MPHF의 단점이며 데이터의 양에 관계없이 해쉬 충돌이 일어 나지 않도록 하기위해서 본 논문에서는 해쉬함수를 병렬화에 있어서 Heuristic 알고리즘을 적용하여 해쉬 인덱스를 최적화하는 방안을 제안한다. 실험 부분에서는 본 제안방법의 착안점에 따른 우수성을 기존의 방법과 비교하여 보여준다.

According to explosive increase of social network service (SNS), big data analysis methods have been developed by many researchers. Out of the methods, Minimal Perfect Hash Function has been used in big data analysis. The method sometimes cause a hash collision in real applications and results in more analysis time. In order to solve the problem, we propose a Collision Free Indexing algorithm using parallel hash function. For developing our method, we optimize hash index by applying a heuristic concept. In the experimental section, we show an outperformance of out method comparing with an existing method.

There are some applications of military and e-commerce networks, where security of transmitted data on unfriendly environment requires more concern as compared to other design issues like power and energy consumption. Data alterations in above mentioned applications can lead to irreparable losses; so to avoid such losses, we have to maintain Data Integrity in the communication network. This paper presents a novel and reliable Hash algorithm which inherits the basic architecture of SHA-1. Performance of proposed technique is compared with existing techniques through statistical test suite for random numbers. Results reveal that the suggested technique is more effective in terms of randomness than the existing algorithms. The proposed technique, thus, finds its applicability in the sensitive data environment.

최근 수동형 태그에 적용 가능한 경량의 AES 대칭키 알고리즘의 연산회로가 개발되면서, RFID 시스템에 AES 대칭키 암호화 기법을 이용한 보안 프로토콜이 제안되고 있다. 본 논문은 수동형 태그에 부착된 경량의 AES 연산기와 난수 발생기를 이용한 RFID 시스템의 보안 강화 프로토콜을 제안하였다. 제안 프로토콜은 서버, 리더, 태그에 모두 AES 알고리즘과 난수생성기가 있으며, 매 세션마다 난수에 의해 다른 비밀키로 메시지를 암호화하여 전송한다. 리더와 태그의 상호인증은 태그난수와 리더난수를 이용하였다. 본 논문의 제안 프로토콜은 기존 상호인증 프로토콜의 인증단계를 줄이고, 태그의 연산량을 감소였으며, 리더와 태그간 Air Zone의 통신단계를 줄임으로서, 모든 공격유형에 견고하고 안전한 프로토콜로서 증명되었다.

Recently arithmetic circuit of lightweight AES symmetric key algorithm that can apply to passive tag have been developed, then security protocol of RFID system using AES symmetric encryption techniques have been proposed. This paper proposed security enhancement protocol of RFID system using lightweight AES arithmetic circuit and random number generator of passive tag. The proposed protocol have AES algorithm and random number generator at server, reader, tag, and transmit encrypted message by separate secret key using random number at each session. The mutual authentication of tag and reader used reader random number and tag random number. As a result, proposal protocol reduce authentication steps of the existing mutual authentication protocol, and reduce amount of computation of tag, and demonstrate as secure protocol to every attack type of attacker by decrease communication step of Air Zone.

At present the hash algorithm analysis is mostly confined to the randomness of the hash values. Researchers have not analyzed the effect of hash algorithm in the network equipment. We propose three evaluation measures of hash algorithm from the perspective of theory analysis and experimental evaluation: the output stream integrity by combining with the dictionary sorting and binary search method to verify, the flow distribution uniformity of hash algorithm, load balancing effect according to the group packet number variance and the max-min packet number ratio. In the experiments, we evaluate the hash algorithm of the current domestic well-known network equipment manufacturers with the backboneflow. The results show that the evaluation measure can effectively measure hash algorithm. It network is helpful for network equipment manufacturers to choose proper hash algorithm.

It is increasing to use ID card and passport for identification as development of information communication technology on 21century. But image of human face that uses for e-passport and admission tag is inserted on RFID chip without any encryption process, or is encrypted using general encryption process. These demands are ever increasing in such business circles, as e-trade businesses where various e-documents go through complex routes and the ownerships of the documents are transferred through a number of parties, and logistics, legal and pharmaceutics circles in which the subjects who record, maintain and read e-documents continue changing. The existing encryption algorithms to ensure the originality of e-documents generally encode the whole area of documents with a symmetric key, so if a user discloses the corresponding symmetric key, it becomes impossible to secure the safety of related documents. In addition, the algorithms have a disadvantage that a user should show the entire information including unnecessary parts (unwanted parts) to receivers in case the entire area of a document is encrypted. This study, thus, proposes a scrambling encryption technique, by which a user, while issuing a registered e-document to a third party, can send partial data of the document, not the entire information, in order to prevent unnecessary leaking of information, improve the readability of documents and use a hash function instead of a complicated encryption process in changing values of image pixels to relocate the image. The proposed system is designed, implemented and tested in performance. In the test, the safety and the operation speed of the system are measured, and with test results, the system is verified in validity and superiority..

During the past time information on internet increasing enormously which greed the attacker and invite them for attack. In order to provide protection from illegal access the concept of Intrusion Detection System (IDS) is introduced. Intrusion detection system recognized as a powerful tool for identifying malicious attacks over the network. IDS works on the concept of string matching with the help of Detection engine. Detection engine of IDS uses String matching algorithm for comparing against malicious activities. This comparison takes enough processing time nearly 70% of the whole IDS processing time by improving performance of searching algorithm. In this paper, we proposed an enhanced version of Hash-Boyer-Moore-Horspool string matching algorithm by adding a single digit hash function for reduced the number of character comparisons and improve the efficiency of IDS by reducing the number of false positive match.

Aiming to solve the problem of long table look-up time in table look-up of CAVLC (Context-based Adaptive Variable Length Coding) for H.264/ AVC, a quick table look-up algorithm based on hash query (TLHQ) is proposed to reduce table look-up time for CAVLC decoding in this paper. The basic idea of the new algorithm is that it uses query technology of hash table to rapidly determine code length based on the number of zero in code prefix, As a result, it can save a lot of time of table looking-up and code judging. Experimental results show that our supposed new algorithm could reduce about 20% table look-up time and save 1056 byte storage space for CAVLC decoding in H.264/AVC.

In the high-speed backbone network, with the increasing speed of network link, the number of network flows increase rapidly. Meanwhile, with restrictions on hardware computing and storage resources, so, how to identify and measure large flows timely and accurately in massive data become a hot issue in high speed network flow measurement area. In this paper, we propose a new algorithm based on double hash algorithm to realize large flow frequent items identification, according to the defect of MF algorithm which produces false positive easily and frequent updates to bring the huge pressure to the system. The complexity and false positive rate of the algorithm was analyzed. The effect of large flow frequent items statistical accuracy and discard rate for parameter configuration was analyzed through simulation. The theoretical analysis and the simulation result indicate that compare to MF algorithm, our algorithm can identify large flow frequent items more accurately, and satisfies the need of actual measurement.

The article introduces a robust and secure and robust hash algorithm based on the DLP over Finite Fields and an iterated hash structure. The Compression Function, CF(B_i, R_i), operates over a finite field of prime P and handles input messages of any length, producing a 512-bit message digest. Input messages are padded to 512 bits or its multiples, which is divided into 512-bit blocks B_d and processed iteratively. Each block's output, R_i, is used in the next iteration until R_i ≥ 512 bits, where it undergoes an XOR operation. The final result, R_d, forms the 512-bit hash digest Y. The algorithm addresses computationally hard problems, offering resistance to brute force attacks and outperforming MD-5 and its variants in security. Experimental analysis demonstrates high security and dependability using Avalanche Parameter and Hamming Distance. The order of complexity is calculated, and a practical implementation for authenticating online accounts is discussed.

본 논문은 인터넷 보안 및 인증에 널리 사용되는 해쉬 알고리즘인 HAS-160을 하드웨어로 구현하였다. 구현을 위해서는 VHDL을 사용하여 모델링 하였으며 또한 단계연산에 필요한 연산들의 최적화된 스케줄링으로 동작속도를 증가 시켰다.

Information on isotopic composition and geometric structure is necessary for identifying a true warhead. Nevertheless, such classified information should be protected physically or electronically. With a novel Hash encryption algorithm, this paper presents a Monte Carlo-based design of a neutron activation analysis verification module. The verification module employs a thermal neutron source, a non-uniform mask (physically encrypting information about isotopic composition and geometric structure), a gamma detector array, and a Hash encryption algorithm (for electronic encryption). In the physical field, a non-uniform mask is designed to distort the characteristic gamma rays emitted by the inspected item. Furthermore, as part of the Hash algorithm, a key is introduced to encrypt the data and improve the system resolution through electronic design. In order to quantify the difference between items, Hamming distance is used, which allows data encryption and analysis simultaneously. Simulated inspections of simple objects are used to quantify system performance. It is demonstrated that the method retains superior resolution even with 1% noise level. And the performances of anti-statistical attack and anti-brute force cracking are evaluated and found to be very excellent. The verification method lays a solid foundation for nuclear disarmament verification in the upcoming era.

Deduplication technique can expand the lifespan and capacity of flash memory-based storage devices by eliminating duplicated write operations. The deduplication techniques can be classified into two approaches, i.e., online and offline approaches. We propose an offline deduplication technique that uses a lightweight hash algorithm, whereas the previous offline technique uses a high-cost hash algorithm. Therefore, the memory space for caching hash values can be reduced, and more pages can be examined for deduplication during short idle intervals. As a result, it can provide shorter write latencies compared to the online approach, and can show low garbage collection costs compared to the previous offline deduplication technique.

해시 함수는 암호 모듈, 암호 제품에서 무결성, 인증, 전자서명 등의 기능을 제공하기 위해 필수적으로 사용되는 암호 프리미티브이다. 본 논문에서는 암호 알고리즘이 제대로 구현되었는지 평가하는 암호 알고리즘 구현 적합성 검정 프로그램(CAVP)이라는 개념과 테스트 방법을 이용하여 SHA-3로 선정된 KECCAK 알고리즘의 구현 적합성 검정 프로그램을 개발하였다. 또한 SHA-3의 구조 분석을 통해 CAVP에 맞는 SHA-3 알고리즘을 16bit-UICC상에 구현하였으며 현재 표준 해시 함수인 SHA-2 알고리즘과의 효율성 비교 분석을 수행하였다.

A hash function is an essential cryptographic algorithm primitive that is used to provide integrity to many applications such as message authentication codes and digital signatures. In this paper, we introduce a concept and test method for a Cryptographic Algorithm Validation Program (CAVP). Also, we design an SHA-3 CAVP program and implement an SHA-3 algorithm in 16bit-UICC. Finally, we compare the efficiency of SHA-3 with SHA-2 and evaluate the exellence of the SHA-3 algorithm.

해시 함수는 데이터의 위변조를 확인하기 위해 사용하는 일방향 함수로, 현재 많은 기술 및 논문에서 해시 함수를 사용하고 있다. 대표적인 해시 함수에는 MD와 SHA가 있으며 다양한 버전을 가지고 있다. 본 논문에서는 해시 알고리즘들의 안전성과 관련된 동향과 취약점을 파악하고 향후 방향성을 알아보고자 한다.

해시 함수는 데이터의 위변조를 확인하기 위해 사용하는 일방향 함수로, 현재 많은 기술 및 논문에서 해시 함수를 사용하고 있다. 대표적인 해시 함수에는 MD와 SHA가 있으며 다양한 버전을 가지고 있다. 본 논문에서는 해시 알고리즘들의 안전성과 관련된 동향과 취약점을 파악하고 향후 방향성을 알아보고자 한다.