diff options
Diffstat (limited to 'docs/hazmat/primitives/symmetric-encryption.rst')
| -rw-r--r-- | docs/hazmat/primitives/symmetric-encryption.rst | 23 |
1 files changed, 18 insertions, 5 deletions
diff --git a/docs/hazmat/primitives/symmetric-encryption.rst b/docs/hazmat/primitives/symmetric-encryption.rst index c98b3814..bca78354 100644 --- a/docs/hazmat/primitives/symmetric-encryption.rst +++ b/docs/hazmat/primitives/symmetric-encryption.rst @@ -20,9 +20,9 @@ provides secrecy but not authenticity. That means an attacker can't see the message but an attacker can create bogus messages and force the application to decrypt them. -For this reason it is *strongly* recommended to combine encryption with a -message authentication code, such as :doc:`HMAC </hazmat/primitives/mac/hmac>`, in -an "encrypt-then-MAC" formulation as `described by Colin Percival`_. +For this reason it is **strongly** recommended to combine encryption with a +message authentication code, such as :doc:`HMAC </hazmat/primitives/mac/hmac>`, +in an "encrypt-then-MAC" formulation as `described by Colin Percival`_. .. class:: Cipher(algorithm, mode, backend) @@ -134,8 +134,8 @@ Algorithms .. versionadded:: 0.4 - SEED is a block cipher developed by the Korea Information Security Agency ( - KISA). It is defined in :rfc:`4269` and is used broadly throughout South + SEED is a block cipher developed by the Korea Information Security Agency + (KISA). It is defined in :rfc:`4269` and is used broadly throughout South Korean industry, but rarely found elsewhere. :param bytes key: The secret key. This must be kept secret. ``128`` bits in @@ -275,6 +275,19 @@ Modes Must be the same number of bytes as the ``block_size`` of the cipher. Do not reuse an ``initialization_vector`` with a given ``key``. +.. class:: CFB8(initialization_vector) + + CFB (Cipher Feedback) is a mode of operation for block ciphers. It + transforms a block cipher into a stream cipher. The CFB8 variant uses an + 8-bit shift register. + + **This mode does not require padding.** + + :param bytes initialization_vector: Must be random bytes. They do not need + to be kept secret and they can be included in a transmitted message. + Must be the same number of bytes as the ``block_size`` of the cipher. + Do not reuse an ``initialization_vector`` with a given ``key``. + .. class:: GCM(initialization_vector, tag=None) .. danger:: |