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| author | Paul Kehrer <paul.l.kehrer@gmail.com> | 2013-12-03 18:58:14 -0600 |
|---|---|---|
| committer | Paul Kehrer <paul.l.kehrer@gmail.com> | 2013-12-03 19:00:09 -0600 |
| commit | 672843712d6b42404fea27a07a87b70d850cc0dd (patch) | |
| tree | 4cc5e7a8933a6a916bbf7a2712df143d6e2ceb71 /docs/hazmat/primitives/symmetric-encryption.rst | |
| parent | cd28a7cca32c734ddd7f7ad353b27b2cf276aa6e (diff) | |
| download | cryptography-672843712d6b42404fea27a07a87b70d850cc0dd.tar.gz cryptography-672843712d6b42404fea27a07a87b70d850cc0dd.tar.bz2 cryptography-672843712d6b42404fea27a07a87b70d850cc0dd.zip | |
link to NIST GCM PDF where NIST recommends 96-bit IV for perf with GCM
Clarify that 96-bit IV is only recommended in performance critical
situations...otherwise feel free to use something longer.
Diffstat (limited to 'docs/hazmat/primitives/symmetric-encryption.rst')
| -rw-r--r-- | docs/hazmat/primitives/symmetric-encryption.rst | 12 |
1 files changed, 7 insertions, 5 deletions
diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst index bb0308bc..8d8d558b 100644 --- a/docs/hazmat/primitives/symmetric-encryption.rst +++ b/docs/hazmat/primitives/symmetric-encryption.rst @@ -342,11 +342,12 @@ Modes :param bytes initialization_vector: Must be random bytes. They do not need to be kept secret (they can be included - in a transmitted message). Recommended - to be 96-bit by NIST, but can be up to - 2\ :sup:`64` - 1 bits. Do not reuse an - ``initialization_vector`` with a given - ``key``. + in a transmitted message). NIST + `recommends 96-bit IV length`_ for + performance critical situations, but it + can be up to 2\ :sup:`64` - 1 bits. + Do not reuse an ``initialization_vector`` + with a given ``key``. :param bytes tag: The tag bytes to verify during decryption. Must be provided for decryption, but is ignored when encrypting. @@ -384,3 +385,4 @@ Insecure Modes .. _`described by Colin Percival`: http://www.daemonology.net/blog/2009-06-11-cryptographic-right-answers.html +.. _`recommends 96-bit IV length`: http://csrc.nist.gov/groups/ST/toolkit/BCM/documents/proposedmodes/gcm/gcm-spec.pdf |