authenticatietags
An authentication tag, or auth tag, is a short data piece that accompanies a message to verify its integrity and origin. They are used in digital communications to ensure a message has not been altered and that it was created with a valid key. Authentication tags enable verification of authenticity as well as integrity, and may be part of an authenticated encryption scheme or used as separate MACs or signatures.
In cryptography, authentication tags are commonly produced by AEAD algorithms such as GCM or ChaCha20-Poly1305. After
The tag length varies by algorithm, typically 8 to 16 bytes in modern schemes; longer tags reduce
Outside cryptography, authentication tags appear in physical security and supply chains, including anti-counterfeit labels, RFID or
Related concepts include MACs, digital signatures, and authenticated encryption schemes. Common implementations and standards appear in