Cryptography
Triple DES (3DES)
Also known as: 3DES, TDES, TDEA
Definition
A legacy block cipher that applies the DES algorithm three times with two or three keys to extend its key length; now retired by NIST and considered obsolete.
Examples
- Older EMV chip-and-PIN payment systems used 3DES for PIN encryption.
- Cisco IPsec VPNs historically offered 3DES as a transitional algorithm.
Related terms
DES (Data Encryption Standard)
An obsolete 64-bit block cipher with a 56-bit key, standardized by NBS in 1977 and now considered broken because its key space can be exhausted in hours.
AES (Advanced Encryption Standard)
A NIST-standardized 128-bit block cipher with 128-, 192- or 256-bit keys, designed by Daemen and Rijmen and used as the dominant symmetric cipher worldwide.
Block Cipher
A symmetric cipher that encrypts fixed-size blocks of plaintext with a secret key, usually combined with a mode of operation to handle data of arbitrary length.
Symmetric Encryption
An encryption scheme in which the same secret key is used for both encryption and decryption, offering high speed and strong confidentiality when the key is shared securely.
Encryption
The cryptographic transformation of plaintext into ciphertext using an algorithm and key so that only authorized parties can recover the original data.
Cipher Suite
A named combination of cryptographic algorithms — key exchange, authentication, bulk encryption, and integrity — negotiated by protocols such as TLS for a given session.