ChaCha20-Poly1305 Cipher Suites for Transport Layer Security (TLS)
draft-ietf-tls-chacha20-poly1305-03
Network Working Group A. Langley
Internet-Draft W. Chang
Updates: 5246, 6347 (if approved) Google Inc
Intended status: Standards Track N. Mavrogiannopoulos
Expires: June 2, 2016 Red Hat
J. Strombergson
Secworks Sweden AB
S. Josefsson
SJD AB
November 30, 2015
ChaCha20-Poly1305 Cipher Suites for Transport Layer Security (TLS)
draft-ietf-tls-chacha20-poly1305-03
Abstract
This document describes the use of the ChaCha stream cipher and
Poly1305 authenticator in the Transport Layer Security (TLS) and
Datagram Transport Layer Security (DTLS) protocols.
Status of This Memo
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This Internet-Draft will expire on June 2, 2016.
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. ChaCha20 Cipher Suites . . . . . . . . . . . . . . . . . . . 3
3. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 4
4. Security Considerations . . . . . . . . . . . . . . . . . . . 4
5. Acknowledgements . . . . . . . . . . . . . . . . . . . . . . 5
6. References . . . . . . . . . . . . . . . . . . . . . . . . . 5
6.1. Normative References . . . . . . . . . . . . . . . . . . 5
6.2. Informative References . . . . . . . . . . . . . . . . . 6
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 7
1. Introduction
This document describes the use of the ChaCha stream cipher and
Poly1305 authenticator in version 1.2 or later of the the Transport
Layer Security (TLS) [RFC5246] protocol, as well as version 1.2 or
later of the Datagram Transport Layer Security (DTLS) protocol
[RFC6347].
ChaCha [CHACHA] is a stream cipher developed by D. J. Bernstein in
2008. It is a refinement of Salsa20, which is one of the selected
ciphers in the eSTREAM portfolio [ESTREAM], and was used as the core
of the SHA-3 finalist, BLAKE.
The variant of ChaCha used in this document has 20 rounds, a 96-bit
nonce and a 256-bit key, and will be referred to as ChaCha20. This
is the conservative variant (with respect to security) of the ChaCha
family and is described in [RFC7539].
Poly1305 [POLY1305] is a Wegman-Carter, one-time authenticator
designed by D. J. Bernstein. Poly1305 takes a 256-bit, one-time
key and a message, and produces a 16-byte tag that authenticates the
message such that an attacker has a negligible chance of producing a
valid tag for an inauthentic message. It is also described in
[RFC7539].
ChaCha and Poly1305 have both been designed for high performance in
software implementations. They typically admit a compact
implementation that uses few resources and inexpensive operations,
which makes them suitable on a wide range of architectures. They
have also been designed to minimize leakage of information through
side channels.
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Recent attacks [CBC-ATTACK] have indicated problems with the CBC-mode
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