Does AES need additional HMAC hash protection after encryption?

AES encryption: Do I need HMAC protection?

When learning the Go language AES encryption example, you may find an important tip: ciphertext requires additional authentication. This raises questions about whether HMAC hash protection is required after AES encryption. It is recommended to transmit the AES encrypted ciphertext together with the HMAC hash value. The receiver first verifies the hash value to confirm the integrity of the ciphertext and prevent data tampering.

However, AES encryption has multiple modes, such as CBC and GCM. GCM mode is an AEAD (authentication encryption) mode, which ensures data confidentiality and integrity. Therefore, no additional HMAC hash is required when using GCM mode.

The Go language standard library supports both CBC mode and GCM mode. The example you see may be in CBC mode, which itself does not provide authentication functionality. Therefore, when using CBC mode, HMAC hash must be used to ensure data integrity.

Conclusion: There is no need for HMAC when using GCM mode; if using CBC mode, HMAC must be used to ensure data integrity. Choosing the right encryption mode and authentication mechanism is crucial.

The above is the detailed content of Does AES need additional HMAC hash protection after encryption?. For more information, please follow other related articles on the PHP Chinese website!