• Journal of the Korea Institute of Information Security & Cryptology
• /
• v.31 no.3
• /
• pp.527-532
• /
• 2021

In this paper, we propose an efficient finite field computation method for Rainbow algorithm, which is the only multivariate quadratic-equation based digital signature among the current US NIST PQC standardization Final List algorithms. Recently, Chou et al. proposed a new efficient implementation method for Rainbow on the Cortex-M4 environment. This paper proposes a new multiplication method over the finite field that can reduce the number of XOR operations by more than 13.7% compared to the Chou et al. method. In addition, a multiplicative inversion over that can be performed by a 4x4 matrix inverse instead of the table lookup method is presented. In addition, the performance is measured by porting the software to which the new method was applied onto RaspberryPI 3B+.

• Bulletin of the Korean Mathematical Society
• /
• v.53 no.5
• /
• pp.1439-1446
• /
• 2016

The execution complexities of the major time memory data tradeoff methods are analyzed in this paper. The multi-target tradeoffs covered are the classical Hellman, distinguished point, and fuzzy rainbow methods, both in their non-perfect and perfect table versions for the latter two methods. We show that their computational complexities are identical to those of the corresponding single-target methods executed under certain matching parameters and conclude that the perfect table fuzzy rainbow tradeoff method is most preferable.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• v.7 no.4
• /
• pp.209-214
• /
• 1974

The utilization dietary protein in young rainbow trout was investigated when feeded with the diets of controlled levels of casein and lipids for 12 days. The composition of the diet is shown in Table 1. Body weight gain was in proportion to the protein content in diet up to $40\%$, ana the maximum was obtained with $40.4\%$ of crude protein (Fig. 1, Table 2). On the other hand, the accumulated protein in body also showed almost maximum value around 40n of protein level in the diet and: the change of accumulated protein showed a little with more-protein level(Fig. 3, Table 9). The protein accumulation rate (protein accumulated/protein consumed) showed its highest value at about $40\%$ of protein level, while the protein utilization value (protein accumulation rate x protein content of diet) attained its highest value at $54.8\%$ of protein level (Table 3). With the above results it is observed that the requirement of dietary protein for young rainbow trout is about $40\%$ of protein in the diet when casein is used as the sole protein source. In protein efficiency ratio (PER) the lower protein level in the diet, the higher PER yields and the more the quantity of protein increases, the more PER decreases and its relation could be figured out as an equation of y=4.91-0.034x (Fig.4), Nose measured PER utilizing the diet which result of this, it is reported that PER rate of casein dropped within the extent of $25\%$ protein in diet. The reason why such a different PER rate appeared at the low protein level is revealed as the carbohydrate is low but the lipid high in capacity of utililzing nutrients for rainbow trout. The relation between the protein content of diet and the conversion factor, feed efficiency were determined and the results are shown in Fig. 2.

• Journal of the Korean Graphic Arts Communication Society
• /
• v.18 no.1
• /
• pp.35-45
• /
• 2000

Recently, as the prepress mainstream is changed to the digital workflow, various digital proofing systems such as high price dye sublimation printers and low price ink jet printers are widely used in printing industry. However, most of the digital proofing devices have lower resolution than analog proofing systems and differ with actual color presses in the color gamuts. Therefore, proper color compensations are needed for digital color proofing in order to match colors between the proofs and the press sheets. This study shows the application method of Look-up Table to the digital color proofer of Rainbow, the analog proofer of Matchprint-II, and an actual offset press is effective on the color compensations.

• Journal of Computing Science and Engineering
• /
• v.9 no.1
• /
• pp.1-8
• /
• 2015

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 $U=\{0,{\ldots},m-1\}$, 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.

• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.34 no.1C
• /
• pp.28-36
• /
• 2009

Time-memory trade-off (TMTO) cryptanalysis proposed by Hellman can be applied for the various crypto-systems such as block ciphers, stream ciphers, and hash functions. In this paper, we propose a novel method to reduce memory size for storing TMTO tables. The starting points in a TMTO table can be substituted by the indices of n-bit samples from a sequence in a family of pseudo-random sequences with good cross-correlation, which results in the reduction of memory size for the starting points. By using this method, it is possible to reduce the memory size by the factor of 1/10 at the cost of the slightly increasing of operation time in the online phase. Because the memory is considered as more expensive resource than the time, the TMTO cryptanalysis will be more feasible for many real crypto systems.