Encryption algorithms help in the procedure of processing the plain text into encrypted text. It reprocesses back in plain text to provide security to electronic data when it gets departed over various networks. Hackers or other unauthorized users are generally unable to to get access such information. Algorithm developers should stay updated in the field of technology to maintain efficient encryption algorithms.

An encryption algorithm has two dimensions that are symmetric key encryptions and public-key encryption. The blowfish algorithm is the symmetric algorithm. It uses the same key for encryption as well as for decryption. It is like a password that needs to be kept secret from unauthorized people. Only the sender-receiver has the authority to access it. Public Key encryption algorithms use two keys.

One of them is for encryption. The other is for decryption. The “public key” that is using for encryption doesn’t require authorized access. The message sender uses the public key to encrypt the message. The authorized recipient uses the private key present with him to decrypt the message. Therefore Blowfish Algorithm in cryptography and network security has played a vital role.

  1. What is the blowfish algorithm?
  2. Advantages of Blowfish Algorithm
  3. Blowfish Algorithm steps
  4. Blowfish Algorithm in Java
  5. Blowfish algorithm explanation

1) What is the blowfish algorithm?

The blowfish encryption algorithm functions as an effective block cipher. The block cipher utilizes the same amount of fixed plaintext and transmits it into ciphertext. The blowfish algorithm is divided into fixed-length blocks of 64 bits. The message which is unencrypted in multiple of eight bites must get augmented. The use of blowfish can be discovered in various segments starting from e-commerce to electronic data management. It is also used in developing secured passwords. 

The two parts of the blowfish algorithm are an expansion of key and encryption of data. During the processing at the expansion stage, the input key is converted into several subkey arrays equivalent to 4168 bytes. 

2) Advantages of Blowfish Algorithm

Blowfish is the most effective and efficient block cipher in common use, except when changing keys. It requires pre-processing which is equivalent to encryption of 4 Kilobytes. Therefore, it has a fewer amount of operations in comparison to other encryption algorithms.

The unique feature of the blowfish algorithm is that it is unclaimed, therefore unrestricted to use. It is much faster than other algorithms such as Data Encryption Standard (DES). 

3) Blowfish Algorithm steps.

1. Eighteen- 32-bit subkeys are possessed by P-array, in a sequence of  P1, P2…., till P18.

2. It also possesses four 32-bit S-boxes with 256 entries in each round:

The generation for subkeys involves the following steps:

Step 1: Initialize first the P-array and then the four S-boxes, in order, with a fixed string. Hexadecimal Digits are present in the given string.

the following example:

 P1 = 0x253f6a89

P2 = 0x88a308d3

P3 = 0x12198a2e

P4 = 0x03707394

This Feistel network of blowfish algorithm consists of 16 rounds. The input is a 64-bit data element, X.

After the string gets finalized, the first 32 bits of the key are XORed with P1. The second 32 bits of the key are XORed with P2. The process goes on till all the strings are finalized. Blowfish algorithm and the redefined P-array are used to encrypt an all-zero string to obtain the 64-bit block. Then the first 32 bits of output for P1 and the second 32 bits of output for P2 ( from the 64-bit block). 

The next step is to get a new 64-bit block is to use the 64-bit output as input back into the blowfish cipher.

The subsequent values in the P-Array are replaced with the block. These steps are repeated for all the values in the P-array and all the S boxes in order. There are 521 iterations needed to generate these processes.

4) Blowfish Algorithm in Java

Blowfish algorithm is used to generate a symmetric key by

It works for key size 128, 256, and 448 bits. 

5) Blowfish algorithm explanation

The key generation involves various steps. Before the encryption, the subkeys get generated. The complicated steps involved in the generation of subkeys prevents the algorithm from cryptanalysis. Blowfish algorithm in cryptography resembles symmetric key cryptography in which the key used for encryption is similar to that of the key used for decryption. It requires the distribution of keys before the transmission of information. The key plays a vital role in this cryptography since the security directly depends on the nature of the key length. The message which needs to be transmitted can be a medical test report, up-gradation of firmware, etc. 


Blowfish Algorithm can achieve efficient data encryption up to 4 bits per clock. It is a variable-length key block cipher. It is fit for applications where the key is more consistent, for example, a communication link. Blowfish is a 16 rounds block encryption algorithm that is very secured. BLOWFISH is frequent and consistently used since it has gone through repetitive tests. It is efficient due to its taking advantage of built-in instructions on the current microprocessors for basic-bit shuffling operations. The advanced algorithm can be invented for future enhancement. It is required for better security, to encrypt a more complicated image.

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