DESIGN AND DEVELOPMENT OF AN ENCRYPTION AND DECRYPTION APPLICATION FOR THE SQL PERMIKOMAS DATABASE USING THE BLOWFISH ALGORITHM

Abstract

To protect the data or information stored in an SQL database, encryption is used. There are many encryption algorithms available, one of which is the Blowfish algorithm. The Blowfish algorithm is a modern symmetric key block cipher. Encryption is performed using a specific key, which produces ciphertext that is unreadable. This ciphertext can be reverted to its original form if decrypted using the same key. The Blowfish algorithm operates through 16 rounds and takes an input of 448 bits. This 448-bit data is divided into two parts, XL and XR, each consisting of 224 bits. Next, the operations XL = XL XOR Pi and XR = F(XL) XOR XR are performed, and then XL and XR are swapped; this process is repeated 16 times. In the 17th round, the operations XR = XR XOR P17 and XL = XL XOR P18 are carried out, and finally, XL and XR are combined back into 448 bits to produce the ciphertext. By using the Blowfish algorithm, the data in the SQL database—including the database itself, tables, fields, and records—remains unreadable due to encryption, so that only authorized users can access the contents by decrypting it. Keywords: Blowfish Algorithm, encryption, decryption, symmetric key.