Hybrid AES-Huffman Coding for Secure Lossless Transmission

Encoding is one of the effective ways to secure files, both for storing and sending files through the public network. Advanced Encryption Standard (AES) is one of the most powerful encryption algorithms that are widely used in various researches and implemented in hardware and software. But this algorithm has negative side effects, which can increase file size. The lossless Huffman compression algorithm can be used to overcome these side effects. But after reviewing the relevant research, the effect of compression on encrypted files is not discussed in detail. This research proposes a combination of AES-Huffman to produce lossless compressed encryption files. Where encryption is done first, then the compression process is carried out. To find out the quality of file security, measurements were made using the avalanche effect (AE) and entropy after encryption and compression. Based on the test results it is proven true that AES encryption has side effects in increasing file size around 25% of the original file size. But after Huffman compression the encrypted file code shrank by around 30%, meaning that the file size after being compressed was smaller than the original file size. However, from the aspect of security, the Huffman file gives a positive effect, where there is a significant increase in the value of AE and entropy.