Editing Stream cipher (section)

==Usage==
Stream ciphers are often used for their speed and simplicity of implementation in hardware, and in applications where plaintext comes in quantities of unknowable length like a secure [[wireless network|wireless]] connection. If a [[block cipher]] (not operating in a stream cipher mode) were to be used in this type of application, the designer would need to choose either transmission efficiency or implementation complexity, since block ciphers cannot directly work on blocks shorter than their block size. For example, if a 128-bit block cipher received separate 32-bit bursts of plaintext, three quarters of the data transmitted would be [[padding (cryptography)|padding]]. Block ciphers must be used in [[ciphertext stealing]] or [[residual block termination]] mode to avoid padding, while stream ciphers eliminate this issue by naturally operating on the smallest unit that can be transmitted (usually bytes).

Another advantage of stream ciphers in military cryptography is that the cipher stream can be generated in a separate box that is subject to strict security measures and fed to other devices such as a radio set, which will perform the XOR operation as part of their function. The latter device can then be designed and used in less stringent environments.

[[ChaCha20|ChaCha]] is becoming the most widely used stream cipher in software;<ref>{{Cite web|url=https://blog.cloudflare.com/do-the-chacha-better-mobile-performance-with-cryptography/|title = Do the ChaCha: Better mobile performance with cryptography|date = 23 February 2015}}</ref> others include: 
[[RC4]],
[[A5/1]],
[[A5/2]],
[[Chameleon (cipher)|Chameleon]], 
[[FISH (cipher)|FISH]], 
[[Helix (cipher)|Helix]],
[[ISAAC (cipher)|ISAAC]], 
[[MUGI]],
[[Panama (cipher)|Panama]],
[[Phelix]], 
[[Pike (cipher)|Pike]],
[[Salsa20]],
[[SEAL (cipher)|SEAL]], 
[[SOBER]],
[[SOBER-128]],
and
[[WAKE (cipher)|WAKE]].