Stream Cipher
Definition
A symmetric cipher that produces a pseudo-random keystream which is XORed bit-by-bit or byte-by-byte with the plaintext. RC4 (legacy), ChaCha20 (current). Stream ciphers can also be built from block ciphers via CTR mode.
Related terms
- AEAD
- Authenticated Encryption with Associated Data. Combines confidentiality and integrity in one primitive. AES-GCM and ChaCha20-Poly1305 are the two modern standards. TLS 1.3...
- AES-NI
- AES New Instructions: hardware AES acceleration introduced on Intel Westmere (2010) and AMD Bulldozer (2011) and now ubiquitous. Single-cycle round operations make...
- Block Cipher
- A symmetric cipher that operates on fixed-size blocks (typically 64 or 128 bits) under a key. AES is a 128-bit-block cipher; DES...
- Constant-Time Crypto
- An implementation whose execution time, memory access pattern and power profile do not depend on the secret key or plaintext. The defence...
- Mode of Operation
- The wrapping protocol that defines how a block cipher handles arbitrary-length data, what IV or nonce is used, and whether integrity is...
Explained in
- Symmetric Cryptosystems: DES, AES, RC4 and BlowfishA symmetric cipher that produces a pseudo-random keystream which is XORed bit-by-bit or byte-by-byte with the plaintext. RC4 (legacy), ChaCha20 (current). Stre...