Complete code sharing of blowfish encryption algorithm in Java language

A few days ago, a rumor suddenly appeared on the Internet: a certain East had a data leak of 12g. Finally, a certain East didn't deny it in a statement. It was reluctantly admitted. A group of people have said what impact it has on ordinary people and what to do, so we won't join the fun. Let's be practical for program apes, Say one encryption algorithm that I personally think is more secure at present: blowfish.

Before coding, let's talk about the features of blowfish encryption algorithm:

1. Symmetric encryption, that is, the encrypted key and the decrypted key are the same; 2. The result after each encryption is different (this is what I appreciate); 3. Reversible, which is different from MD5 and other summary algorithms introduced in my previous article. 4. Fast speed. The encryption and decryption process is basically composed of add and XOR instruction operations; 5. Free, anyone can use it for free without paying copyright fee; 6. Blowfish can only encrypt and decrypt 8 bytes of data at a time ；

Blowfish algorithm is a symmetric block encryption algorithm. The core of the algorithm is sub key generation. It expands the variable length key into a sub key array with a total length of 4168byte. A large number of sub keys are used in the algorithm, and the sub key depends on the user key. In the actual encryption / decryption process, the updated sub key array is used, which is p array and s box. Blowfish algorithm has a core encryption function: BF_ En(), the input of this function is 64 bit plaintext information, which is output in the form of 64 bit ciphertext information after operation. Using blowfish algorithm to encrypt information requires two processes: key preprocessing and information encryption. Similarly, decryption also requires two processes, key preprocessing and information decryption.

Source key of blowfish algorithm -- p@R_747_2419 @And s@R_747_2419 @It is fixed, and if we want to encrypt a message, we need to select a key and use this key to encrypt the message p@R_747_2419 @And s@R_747_2419 @Transform to obtain the key to be used in the next step of information encryption_ p@R_747_2419 @And key_ s@R_747_2419 @。 The same is true for decryption. Since blowfish is a symmetric encryption algorithm, the decryptor generates the key required for decryption according to the key after obtaining the key_@ R_ 747_ 2419 @ and key_ s@R_747_2419 @。 When encrypting and decrypting the same information, different keys will lead to different ciphertext. Therefore, the key of blowfish algorithm lies in key selection and confidentiality.

Because the blowfish algorithm uses variable length key, it not only brings great convenience to users, but also has hidden dangers. Because the core of encryption / decryption algorithm lies in the selection and confidentiality of key, but in practical application, some weak keys are often used to encrypt information resources, resulting in great security risks

Next is the most important part, the implementation of blowfish encryption algorithm:

This is an external interface, which is very simple to use and user-friendly. The following is the specific implementation of the algorithm:

summary

The above is all about the complete code sharing of blowfish encryption algorithm in Java language. I hope it will be helpful to you. Interested friends can continue to refer to other related topics on this site. If there are deficiencies, please leave a message to point out.