Jungjoo Seo

Bio: Jungjoo Seo is an academic researcher from Seoul National University. The author has contributed to research in topics: Load balancing (computing) & Symmetric multiprocessor system. The author has an hindex of 2, co-authored 5 publications receiving 19 citations.

High-Speed Parallel Implementations of the Rainbow Method in a Heterogeneous System

Abstract: The computing power of graphics processing units (GPU) has increased rapidly, and there has been extensive research on general-purpose computing on GPU (GPGPU) for cryptographic algorithms such as RSA, ECC, NTRU, and AES With the rise of GPGPU, commodity computers have become complex heterogeneous GPU+CPU systems This new architecture poses new challenges and opportunities in high-performance computing In this paper, we present high-speed parallel implementations of the rainbow method, which is known as the most efficient time-memory tradeoff, in the heterogeneous GPU+CPU system We give a complete analysis of the effect of multiple checkpoints on reducing the cost of false alarms, and take advantage of it for load balancing between GPU and CPU Our implementation with multiple checkpoints requires no more time on average for resolving false alarms and it actually finishes earlier than generating all online chains unlike other implementations on GPU

High-speed parallel implementations of the rainbow method based on perfect tables in a heterogeneous system

Abstract: The computing power of graphics processing units GPU has increased rapidly, and there has been extensive research on general-purpose computing on GPU GPGPU for cryptographic algorithms such as RSA, Elliptic Curve Cryptosystem ECC, NTRU, and Advanced Encryption Standard. With the rise of GPGPU, commodity computers have become complex heterogeneous GPU+CPU systems. This new architecture poses new challenges and opportunities in high-performance computing. In this paper, we present high-speed parallel implementations of the rainbow method based on perfect tables, which is known as the most efficient time-memory trade-off, in the heterogeneous GPU+CPU system. We give a complete analysis of the effect of multiple checkpoints on reducing the cost of false alarms and take advantage of it for load balancing between GPU and CPU. For GTX460, our implementation is about 1.86 and 3.25 times faster than other GPU-accelerated implementations, RainbowCrack and Cryptohaze, respectively, and for GTX580, 1.53 and 2.40 times faster. Copyright © 2014 John Wiley & Sons, Ltd.

Efficient Accessing and Searching in a Sequence of Numbers

Abstract: Accessing and searching in a sequence of numbers are fundamental operations in computing that are encountered in a wide range of applications. One of the applications of the problem is cryptanalytic time-memory tradeoff which is aimed at a one-way function. A rainbow table, which is a common method for the time-memory tradeoff, contains elements from an input domain of a hash function that are normally sorted integers. In this paper, we present a practical indexing method for a monotonically increasing static sequence of numbers where the access and search queries can be addressed efficiently in terms of both time and space complexity. For a sequence of n numbers from a universe U = {0, ..., m ? 1}, our data structure requires n lg(m/n) + O(n) bits with constant average running time for both access and search queries. We also give an analysis of the time and space complexities of the data structure, supported by experiments with rainbow tables.

A Malicious Traffic Detection Method Using X-means Clustering

Abstract: Malicious traffic, such as DDoS attack and botnet communications, refers to traffic that is generated for the purpose of disturbing internet networks or harming certain networks, servers, or hosts. As malicious traffic has been constantly evolving in terms of both quality and quantity, there have been many researches fighting against it. In this paper, we propose an effective malicious traffic detection method that exploits the X-means clustering algorithm. We also suggest how to analyze statistical characteristics of malicious traffic and to define metrics that are used when clustering. Finally, we verify effectiveness of our method by experiments with two released traffic data.

Cryptographic hardware and embedded systems : CHES 2008 : 10th International Workshop, Washington, D.C., USA, August 10-13, 2008 : proceedings

Abstract: Side-Channel Analysis 1.- Attack and Improvement of a Secure S-Box Calculation Based on the Fourier Transform.- Collision-Based Power Analysis of Modular Exponentiation Using Chosen-Message Pairs.- Multiple-Differential Side-Channel Collision Attacks on AES.- Implementations 1.- Time-Area Optimized Public-Key Engines: -Cryptosystems as Replacement for Elliptic Curves?.- Ultra High Performance ECC over NIST Primes on Commercial FPGAs.- Exploiting the Power of GPUs for Asymmetric Cryptography.- Fault Analysis 1.- High-Performance Concurrent Error Detection Scheme for AES Hardware.- A Lightweight Concurrent Fault Detection Scheme for the AES S-Boxes Using Normal Basis.- RSA with CRT: A New Cost-Effective Solution to Thwart Fault Attacks.- Random Number Generation.- A Design for a Physical RNG with Robust Entropy Estimators.- Fast Digital TRNG Based on Metastable Ring Oscillator.- Efficient Helper Data Key Extractor on FPGAs.- Side-Channel Analysis 2.- The Carry Leakage on the Randomized Exponent Countermeasure.- Recovering Secret Keys from Weak Side Channel Traces of Differing Lengths.- Attacking State-of-the-Art Software Countermeasures-A Case Study for AES.- Cryptography and Cryptanalysis.- Binary Edwards Curves.- A Real-World Attack Breaking A5/1 within Hours.- Hash Functions and RFID Tags: Mind the Gap.- Implementations 2.- A New Bit-Serial Architecture for Field Multiplication Using Polynomial Bases.- A Very Compact Hardware Implementation of the MISTY1 Block Cipher.- Light-Weight Instruction Set Extensions for Bit-Sliced Cryptography.- Fault Analysis 2.- Power and Fault Analysis Resistance in Hardware through Dynamic Reconfiguration.- RFID and Its Vulnerability to Faults.- Perturbating RSA Public Keys: An Improved Attack.- Side-Channel Analysis 3.- Divided Backend Duplication Methodology for Balanced Dual Rail Routing.- Using Subspace-Based Template Attacks to Compare and Combine Power and Electromagnetic Information Leakages.- Mutual Information Analysis.- Invited Talks.- RSA-Past, Present, Future.- A Vision for Platform Security.

An Efficient Elliptic Curve Cryptography Signature Server With GPU Acceleration

Abstract: Over the Internet, digital signature has been an indispensable approach to securing e-commerce and other online transactions requiring authentication. Concerning the computing costs of signature generation and verification, it has become a more and more common practice for security practitioners to outsource such computations from heavily loaded application servers called tenants to dedicated proxies like signature servers in the enterprise private cloud. In this paper, we present our high-performance signature server called Guess . It implements the elliptic curve digital signature algorithm (ECDSA) with 256-b key size on a Linux-powered commodity computer, harnessing a desktop graphics processing unit as a featured cryptographic accelerator. We demonstrate our experience in maximizing the computing power of Guess and also its capability to deliver such power to the tenants, which includes down-to-earth customization and optimization considering various hardware and software factors. Our comprehensive implementation of ECDSA is tested against intensive network traffic. Field experiments show that Guess achieves $T_{s} = 8.71 \times 10^{6}$ operations per second (OPS) for signature generation or $T_{v} = 9.29 \times 10^{5}$ OPS for verification, which is significantly faster than existent prototypes and products. Guess is a universal server that readily supports various categories of elliptic curve cryptographic schemes, such as digital signature, key agreement, and encryption.

Password-Hashing Status

Abstract: Computers are used in our everyday activities, with high volumes of users accessing provided services. One-factor authentication consisting of a username and a password is the common choice to authenticate users in the web. However, the poor password management practices are exploited by attackers that disclose the users’ credentials, harming both users and vendors. In most of these occasions the user data were stored in clear or were just processed by a cryptographic hash function. Password-hashing techniques are applied to fortify this user-related information. The standardized primitive is currently the PBKDF2 while other widely-used schemes include Bcrypt and Scrypt. The evolution of parallel computing enables several attacks in password-hash cracking. The international cryptographic community conducted the Password Hashing Competition (PHC) to identify new efficient and more secure password-hashing schemes, suitable for widespread adoption. PHC advanced our knowledge of password-hashing. Further analysis efforts revealed security weaknesses and novel schemes were designed afterwards. This paper provides a review of password-hashing schemes until the first quarter of 2017 and a relevant performance evaluation analysis on a common setting in terms of code size, memory consumption, and execution time.