Salsa20 & ChaCha20

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Salsa20 and ChaCha20 are symmetric stream ciphers.

• both designed by Daniel J. Bernstein
• are remarkably secure and popular
• not protected by patent
• Salsa20
  • selected as a finalist in the EU’s ECRYPT competition
• ChaCha20
  • adopted by Google as a replacement for RC4 in TLS
  • used in
    • part of the arc4random random number generator used in NetBSD, OpenBSD, and FreeBSD
    • DragonflyBSD
    • Linux kernel as part of the /dev/urandom device
  • IETF published implementation reference in 2015 in RFC 7539