Analisis Performa dan Efisiensi AES-256 Mode CBC untuk Enkripsi Data Nasabah Sintetis

Abstract

The growth of digital banking increases customer data volume while enlarging the risk of data breaches, making encryption both a technical necessity and a regulatory obligation. This study analyzes the performance and efficiency of the 256-bit Advanced Encryption Standard (AES-256) in Cipher Block Chaining (CBC) mode on synthetic data representing five customer-identity fields, using a quantitative method. Testing was conducted across five data-size scenarios (1 KB to 10 MB) with 30 repetitions and 5 warm-ups per scenario, implemented in Java 11 (javax.crypto/JCA), and evaluated by encryption time, decryption time, and throughput. Byte-per-byte validation showed decrypted data identical to the original. Average encryption time increased from 0.4351 ms (1 KB) to 45.9987 ms (10 MB) and decryption time from 0.8032 ms to 89.6645 ms, with encryption throughput reaching 208.86 MB/s and decryption 108.01 MB/s on the largest data. Within these test conditions, AES-256 CBC showed good performance and efficiency, particularly on large data. The findings are limited to the synthetic data, scenarios, and test environment used and are not generalized to banking systems in general; its cryptographic strength rests on NIST FIPS 197 and SP 800-57 rather than direct cryptanalysis. Validation with real datasets is recommended for future work.