Article Per Year (5 Year)
p-Index From 2021 - 2026
0
P-Index
This Author published in this journals
All Journal Indonesian Journal of Electrical Engineering and Informatics (IJEEI) Indonesian Journal of Electrical Engineering and Computer Science
Ruji P Medina
Technological Institute of the Philippines
Computer Science & IT Electrical & Electronics Engineering

Published : 5 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 3 Documents
Search
Journal : Indonesian Journal of Electrical Engineering and Computer Science

 1 
Modified SHA-1 Algorithm Rogel Ladia Quilala; Ariel M Sison; Ruji P Medina
Indonesian Journal of Electrical Engineering and Computer Science Vol 11, No 3: September 2018
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v11.i3.pp1027-1034

Abstract

Hashes are used to check the integrity of data. This paper modified SHA-1 by incorporating mixing method in every round for better diffusion. The modification increased the hash output to 192-bits. Increasing the output increases the strength because breaking the hash takes longer. Based on the different message types, avalanche percentage of modified SHA-1 showed better diffusion at 51.64%, higher than the target 50%, while SHA-1 achieved 46.61%. The average execution time noted for modified SHA-1 is 0.33 seconds while SHA-1 is 0.08 seconds. Time increases as the number of messages hashed increases; the difference is negligible in fewer messages. On character hits, that is - no same character in the same position, modified SHA-1 achieved lower hit rate because of the mixing method added. The modifications’ effectiveness was also evaluated using a hash test program. After inputting 1000 hashes from random strings, the result shows no duplicate hash.
Improving self-organizing map with nguyen-widrow initialization lgorithm Maureen Nettie N Linan; Bobby D Gerardo; Ruji P Medina
Indonesian Journal of Electrical Engineering and Computer Science Vol 15, No 1: July 2019
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v15.i1.pp535-542

Abstract

The quality of cluster result and the learning speed of Self-organizing map (SOM) are dependent on the initialization of weights since the initial values for weight vectors affect the performance of SOM training when applied to clustering. In this paper, improvement of SOM was achieved with the application of the Nguyen-Widrow algorithm to initialize weights. Nguyen-Widrow initialization algorithm is a method for initialization of the weights of neural networks to speed up the training process. Performance of the modified SOM was determined in terms of cluster error rate and the number of iterations to achieve convergence using different datasets and results show that the modified SOM algorithm produces better cluster results and improved training speed compared to traditional SOM.
Modified Blowfish Algorithm Theda Flare Ginoy Quilala; Ariel M Sison; Ruji P Medina
Indonesian Journal of Electrical Engineering and Computer Science Vol 12, No 1: October 2018
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijeecs.v12.i1.pp38-45

Abstract

Cryptography guarantees security in communication through encryption. This paper proposed a modified Blowfish encryption that uses 128-bit block size and 128-bit key to comply with minimum requirements as an encryption standard. The modification retained the original structure for easy migration but utilized two S-boxes to save memory. A derivation was added to prevent symmetry.  The algorithm’s performance was evaluated using time, and avalanche. Upon testing, the modified blowfish is slower with key, encryption, and decryption average of 26.99ms, 1651.83ms, and 2765.04ms compared to blowfish with 21.65ms, 1297.76ms and 2176.59ms due to block size difference. Applying 128-bit block size increases security by decreasing the chances of having duplicate blocks that may leak information. The modified Blowfish is faster compared to Twofish with an encryption and decryption average time of 2418.08ms and 4002.70ms. The added derivation improved the avalanche of the modified blowfish.  Blowfish achieved 47.14% while modified Blowfish attained 52.86%.
Co-Authors Ariel M Sison Bobby D Gerardo Maureen Nettie N Linan Rogel Ladia Quilala Rogel Ladia Quilala Theda Flare Ginoy Quilala Theda Flare Ginoy Quilala