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What is a symmetric encryption algorithm?
2022-02-30

Introduction to Symmetric Encryption Algorithms

Symmetric encryption algorithms, also known as symmetric key encryption or single-key encryption, are early adopted and technologically mature encryption algorithms.

Its working principle involves using the same key for both encryption and decryption operations. During the encryption process, the sender processes the plaintext (original data) and the encryption key through a special encryption algorithm, transforming it into a complex encrypted ciphertext that is then sent out. Upon receiving the ciphertext, the recipient uses the same key and decryption algorithm to decrypt the ciphertext, thereby restoring it to the original plaintext.

Characteristics

  • Same Key: The same key is used for both encryption and decryption.
  • Fast Encryption and Decryption Speed: Because the same key and algorithm are used for both encryption and decryption, the speed of encryption and decryption is relatively fast.
  • Difficult Key Management: The use of symmetric encryption algorithms on distributed network systems is challenging, primarily due to the complexity of key management and the high cost of usage.

Common Symmetric Encryption Algorithms

Common symmetric encryption algorithms include:

  • AES (Advanced Encryption Standard): The Advanced Encryption Standard advocated by the National Institute of Standards and Technology (NIST) in the United States.
  • DES (Data Encryption Standard): A data encryption standard that was once widely used but has gradually been replaced by more secure algorithms such as AES.
  • 3DES (Triple DES): An enhanced version of DES that improves security by using the DES algorithm three times.
  • BlowFish: A block cipher algorithm with a 64-bit block size and variable key length.

Application Scenarios

Symmetric encryption algorithms are suitable for encrypting and decrypting large amounts of data. In application scenarios that require efficient processing of large amounts of data, such as network communications and data storage, symmetric encryption algorithms are widely used.