# Computational Complexity of Modified Blowfish Cryptographic Algorithm on Video Data
###### Abstract
Modern cryptography is primarily reliant on mathematical theory and computer science skills; cryptographic methods are based on computational hardness assumptions, making it difficult for any adversary to crack them in practice [10; 11]. Although breaking into such a well-designed system is theoretically feasible, it is difficult to do so in actual practice. Cryptography is widely acknowledged as one of the most critical components of any organization's security policy, and it is widely accepted as the industry standard for information security, trust, resource management, and electronic financial transactions [12; 13]. In essence, cryptographic algorithms/techniques can be divided into symmetric key cryptographic (using a single key for encoding and decoding) and asymmetric key cryptographic (using a pair of keys for both encoding and decoding of the message) algorithms/techniques. Video encryption is a method of digitally disguising videos to prevent them from being intercepted and seen by unauthorized parties [14]. This method requires the encryption of videos using software and hardware encoding to protect their content. Without first decoding them, no one can access the encrypted videos. In December 1993, [PERSON] designed Blowfish, a symmetric cryptosystem, as a high-capacity algorithm that can be freely used as an alternative to prior encryption schemes. It is one of the most extensively used symmetric cryptographic algorithms for data security. Blowfish is regarded as one of the quickest and easiest symmetric algorithms since it is a generally accessible and license-free cryptography technique [15]. Therefore, this study intends to explore the secured method of the Blowfish algorithm by modifying the structure of the F-function to produce a modified version of the Blowfish algorithm. Both the normal Blowfish and the modified Blowfish algorithm will be used to encrypt video data and compare their performance in terms of time complexity, throughput, and avalanche effect to determine which of the algorithms performs better in terms of time and security usage. This study will spur researchers to design high-impact and more secure computing-encryption algorithms. [PERSON], [PERSON], and [PERSON] [16] investigated the security, DES, and Blowfish cryptography methods' strength and speed requirements, which are extensively used for network data encryption. According to their experiments, the Blowfish algorithm is quicker than DES while consuming about the same amount of electricity. They demonstrated that the Blowfish encryption technique is better suited to the security of wireless network applications. [PERSON] and [PERSON] [17] proposed a novel method of generating random numbers from images. Read the image pixel by pixel, then choose any two colors at random for the precise spot. To mix specific colors, use XOR; then, choose the key sizes. This key is employed in the decryption of plaintext. The Blowfish scheme utilizes this key generation process. Finally, they state that under the symmetrical scheme, this kind of key production is sufficient for shorter keys. [PERSON] and [PERSON] [18] improved the safety of the Blowfish method while reducing the time it takes to encrypt and decrypt data. Choose a number between 0 and 65,535 at random. Set the value of the signal to zero. Transform an arbitrary integer to 16-bit code and look for places with 0 entries; set the flag value to one and zero otherwise. If indeed the signal is present as 1, the F-function will not execute, but it will work if the signal is set to 0. In every round, a randomly chosen number is generated, resulting in a distinction in the implementation of the F function. They discovered that when compared to the original Blowfish algorithm, the encryption and decryption times are reduced. [PERSON], [PERSON], and [PERSON] [19] proposed employing a discrete wavelet transform to secure the data transfer of audio signals. They developed a new hybrid technique for sending messages in a highly secure manner by combining cryptography and steganography.