A MULTI-LEVEL ENCRYPTION TECHNIQUES USING BLOWFISH AND ADVANCED ENCRYPTION STANDARD (AES) TO SECURE JOB PORTAL

Abstract

This study developed a multi-level encryption framework that integrates Blowfish and Advanced Encryption 
Standard (AES) algorithms with Role-Based Access Control (RBAC) in a PHP-based job portal. The methodology 
involved the design and implementation of a secure web application using PHP, MySQL, and OpenSSL libraries. 
Blowfish (via bcrypt) was applied for password hashing, AES-256 for sensitive data encryption, and RBAC for 
access differentiation between users and administrators. System performance was evaluated using metrics such as 
encryption/decryption time, throughput, and input validation. Experimental results showed that Blowfish provided 
strong password protection, while AES-256 achieved efficient encryption of large files such as uploaded CVs. The 
measured encryption time ranged from 0.016 s to 0.043 s, and decryption time from 0.026 s to 0.086 s, with 
throughput values between 820.04 KB/s and 1625.74 KB/s, indicating high processing efficiency for small- to 
medium-sized data. The performance analysis further revealed that throughput generally improved with file size up 
to a threshold, after which minor fluctuations occurred due to computational overhead.