Danger
This is a “Hazardous Materials” module. You should ONLY use it if you’re 100% absolutely sure that you know what you’re doing because this module is full of land mines, dragons, and dinosaurs with laser guns. You may instead be interested in Fernet (symmetric encryption).
Symmetric encryption
Symmetric encryption is a way to encrypt or hide the contents of material where the sender and receiver both use the same secret key. Note that symmetric encryption is not sufficient for most applications because it only 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. In many contexts, a lack of authentication on encrypted messages can result in a loss of secrecy as well.
For this reason in nearly all contexts it is necessary to combine encryption
with a message authentication code, such as
HMAC, in an “encrypt-then-MAC”
formulation as described by Colin Percival. cryptography
includes a
recipe named Fernet (symmetric encryption) that does this for you. To minimize the risk of
security issues you should evaluate Fernet to see if it fits your needs before
implementing anything using this module. If Fernet (symmetric encryption) is not
appropriate for your use-case then you may still benefit from
Authenticated encryption which combines encryption and authentication
securely.
- class cryptography.hazmat.primitives.ciphers.Cipher(algorithm, mode)[source]
Cipher objects combine an algorithm such as
AES
with a mode likeCBC
orCTR
. A simple example of encrypting and then decrypting content with AES is:>>> import os >>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes >>> key = os.urandom(32) >>> iv = os.urandom(16) >>> cipher = Cipher(algorithms.AES(key), modes.CBC(iv)) >>> encryptor = cipher.encryptor() >>> ct = encryptor.update(b"a secret message") + encryptor.finalize() >>> decryptor = cipher.decryptor() >>> decryptor.update(ct) + decryptor.finalize() b'a secret message'
- Parameters:
algorithm – A
CipherAlgorithm
instance such as those described below.
- Raises:
cryptography.exceptions.UnsupportedAlgorithm – This is raised if the provided
algorithm
is unsupported.
- encryptor()[source]
- Returns:
An encrypting
CipherContext
instance.
If the requested combination of
algorithm
andmode
is unsupported anUnsupportedAlgorithm
exception will be raised.
- decryptor()[source]
- Returns:
A decrypting
CipherContext
instance.
If the requested combination of
algorithm
andmode
is unsupported anUnsupportedAlgorithm
exception will be raised.
Algorithms
- class cryptography.hazmat.primitives.ciphers.algorithms.AES(key)[source]
AES (Advanced Encryption Standard) is a block cipher standardized by NIST. AES is both fast, and cryptographically strong. It is a good default choice for encryption.
- Parameters:
key (bytes-like) – The secret key. This must be kept secret. Either
128
,192
, or256
bits long.
- class cryptography.hazmat.primitives.ciphers.algorithms.AES128(key)[source]
Added in version 38.0.0.
An AES class that only accepts 128 bit keys. This is identical to the standard
AES
class except that it will only accept a single key length.- Parameters:
key (bytes-like) – The secret key. This must be kept secret.
128
bits long.
- class cryptography.hazmat.primitives.ciphers.algorithms.AES256(key)[source]
Added in version 38.0.0.
An AES class that only accepts 256 bit keys. This is identical to the standard
AES
class except that it will only accept a single key length.- Parameters:
key (bytes-like) – The secret key. This must be kept secret.
256
bits long.
- class cryptography.hazmat.primitives.ciphers.algorithms.Camellia(key)[source]
Camellia is a block cipher approved for use by CRYPTREC and ISO/IEC. It is considered to have comparable security and performance to AES but is not as widely studied or deployed.
- Parameters:
key (bytes-like) – The secret key. This must be kept secret. Either
128
,192
, or256
bits long.
- class cryptography.hazmat.primitives.ciphers.algorithms.ChaCha20(key, nonce)[source]
Added in version 2.1.
Note
In most cases users should use
ChaCha20Poly1305
instead of this class. ChaCha20 alone does not provide integrity so it must be combined with a MAC to be secure.ChaCha20Poly1305
does this for you.ChaCha20 is a stream cipher used in several IETF protocols. While it is standardized in RFC 7539, this implementation is not RFC-compliant. This implementation uses a
64
bits counter and a64
bits nonce as defined in the original version of the algorithm, rather than the32/96
counter/nonce split defined in RFC 7539.- Parameters:
key (bytes-like) – The secret key. This must be kept secret.
256
bits (32 bytes) in length.nonce (bytes-like) – Should be unique, a nonce. It is critical to never reuse a
nonce
with a given key. Any reuse of a nonce with the same key compromises the security of every message encrypted with that key. The nonce does not need to be kept secret and may be included with the ciphertext. This must be128
bits in length. The 128-bit value is a concatenation of the 8-byte little-endian counter and the 8-byte nonce.
Note
In the original version of the algorithm the nonce is defined as a 64-bit value that is later concatenated with a block counter (encoded as a 64-bit little-endian). If you have a separate nonce and block counter you will need to concatenate it yourself before passing it. For example, if you have an initial block counter of 2 and a 64-bit nonce the concatenated nonce would be
struct.pack("<Q", 2) + nonce
.>>> import struct, os >>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes >>> key = os.urandom(32) >>> nonce = os.urandom(8) >>> counter = 0 >>> full_nonce = struct.pack("<Q", counter) + nonce >>> algorithm = algorithms.ChaCha20(key, full_nonce) >>> cipher = Cipher(algorithm, mode=None) >>> encryptor = cipher.encryptor() >>> ct = encryptor.update(b"a secret message") >>> decryptor = cipher.decryptor() >>> decryptor.update(ct) b'a secret message'
- class cryptography.hazmat.primitives.ciphers.algorithms.TripleDES(key)[source]
Warning
This algorithm has been deprecated and moved to the Decrepit cryptography module. If you need to continue using it then update your code to use the new module path. It will be removed from this namespace in 48.0.0.
Triple DES (Data Encryption Standard), sometimes referred to as 3DES, is a block cipher standardized by NIST. Triple DES has known crypto-analytic flaws, however none of them currently enable a practical attack. Nonetheless, Triple DES is not recommended for new applications because it is incredibly slow; old applications should consider moving away from it.
- Parameters:
key (bytes-like) – The secret key. This must be kept secret. Either
64
,128
, or192
bits long. DES only uses56
,112
, or168
bits of the key as there is a parity byte in each component of the key. Some writing refers to there being up to three separate keys that are each56
bits long, they can simply be concatenated to produce the full key.
- class cryptography.hazmat.primitives.ciphers.algorithms.CAST5(key)[source]
Added in version 0.2.
Warning
This algorithm has been deprecated and moved to the Decrepit cryptography module. If you need to continue using it then update your code to use the new module path. It will be removed from this namespace in 45.0.0.
CAST5 (also known as CAST-128) is a block cipher approved for use in the Canadian government by the Communications Security Establishment. It is a variable key length cipher and supports keys from 40-128 bits in length.
- Parameters:
key (bytes-like) – The secret key, This must be kept secret. 40 to 128 bits in length in increments of 8 bits.
- class cryptography.hazmat.primitives.ciphers.algorithms.SEED(key)[source]
Added in version 0.4.
Warning
This algorithm has been deprecated and moved to the Decrepit cryptography module. If you need to continue using it then update your code to use the new module path. It will be removed from this namespace in 45.0.0.
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.
- Parameters:
key (bytes-like) – The secret key. This must be kept secret.
128
bits in length.
- class cryptography.hazmat.primitives.ciphers.algorithms.SM4(key)[source]
Added in version 35.0.0.
SM4 is a block cipher developed by the Chinese Government and standardized in the GB/T 32907-2016. It is used in the Chinese WAPI (Wired Authentication and Privacy Infrastructure) standard. (An English description is available at draft-ribose-cfrg-sm4-10.) This block cipher should be used for compatibility purposes where required and is not otherwise recommended for use.
- Parameters:
key (bytes-like) – The secret key. This must be kept secret.
128
bits in length.
Weak ciphers
Warning
These ciphers are considered weak for a variety of reasons. New applications should avoid their use and existing applications should strongly consider migrating away.
- class cryptography.hazmat.primitives.ciphers.algorithms.Blowfish(key)[source]
Warning
This algorithm has been deprecated and moved to the Decrepit cryptography module. If you need to continue using it then update your code to use the new module path. It will be removed from this namespace in 45.0.0.
Blowfish is a block cipher developed by Bruce Schneier. It is known to be susceptible to attacks when using weak keys. The author has recommended that users of Blowfish move to newer algorithms such as
AES
.- Parameters:
key (bytes-like) – The secret key. This must be kept secret. 32 to 448 bits in length in increments of 8 bits.
- class cryptography.hazmat.primitives.ciphers.algorithms.ARC4(key)[source]
Warning
This algorithm has been deprecated and moved to the Decrepit cryptography module. If you need to continue using it then update your code to use the new module path. It will be removed from this namespace in 48.0.0.
ARC4 (Alleged RC4) is a stream cipher with serious weaknesses in its initial stream output. Its use is strongly discouraged. ARC4 does not use mode constructions.
- Parameters:
key (bytes-like) – The secret key. This must be kept secret. Either
40
,56
,64
,80
,128
,192
, or256
bits in length.
>>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes >>> algorithm = algorithms.ARC4(key) >>> cipher = Cipher(algorithm, mode=None) >>> encryptor = cipher.encryptor() >>> ct = encryptor.update(b"a secret message") >>> decryptor = cipher.decryptor() >>> decryptor.update(ct) b'a secret message'
- class cryptography.hazmat.primitives.ciphers.algorithms.IDEA(key)[source]
Warning
This algorithm has been deprecated and moved to the Decrepit cryptography module. If you need to continue using it then update your code to use the new module path. It will be removed from this namespace in 45.0.0.
IDEA (International Data Encryption Algorithm) is a block cipher created in 1991. It is an optional component of the OpenPGP standard. This cipher is susceptible to attacks when using weak keys. It is recommended that you do not use this cipher for new applications.
- Parameters:
key (bytes-like) – The secret key. This must be kept secret.
128
bits in length.
Modes
- class cryptography.hazmat.primitives.ciphers.modes.CBC(initialization_vector)[source]
CBC (Cipher Block Chaining) is a mode of operation for block ciphers. It is considered cryptographically strong.
Padding is required when using this mode.
- Parameters:
initialization_vector (bytes-like) – 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. Each time something is encrypted a newinitialization_vector
should be generated. Do not reuse aninitialization_vector
with a givenkey
, and particularly do not use a constantinitialization_vector
.
A good construction looks like:
>>> import os >>> from cryptography.hazmat.primitives.ciphers.modes import CBC >>> iv = os.urandom(16) >>> mode = CBC(iv)
While the following is bad and will leak information:
>>> from cryptography.hazmat.primitives.ciphers.modes import CBC >>> iv = b"a" * 16 >>> mode = CBC(iv)
- class cryptography.hazmat.primitives.ciphers.modes.CTR(nonce)[source]
Warning
Counter mode is not recommended for use with block ciphers that have a block size of less than 128-bits.
CTR (Counter) is a mode of operation for block ciphers. It is considered cryptographically strong. It transforms a block cipher into a stream cipher.
This mode does not require padding.
- Parameters:
nonce (bytes-like) – Should be unique, a nonce. It is critical to never reuse a
nonce
with a given key. Any reuse of a nonce with the same key compromises the security of every message encrypted with that key. Must be the same number of bytes as theblock_size
of the cipher with a given key. The nonce does not need to be kept secret and may be included with the ciphertext.
- class cryptography.hazmat.primitives.ciphers.modes.OFB(initialization_vector)[source]
OFB (Output Feedback) is a mode of operation for block ciphers. It transforms a block cipher into a stream cipher.
This mode does not require padding.
- Parameters:
initialization_vector (bytes-like) – 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 aninitialization_vector
with a givenkey
.
- class cryptography.hazmat.primitives.ciphers.modes.CFB(initialization_vector)[source]
CFB (Cipher Feedback) is a mode of operation for block ciphers. It transforms a block cipher into a stream cipher.
This mode does not require padding.
- Parameters:
initialization_vector (bytes-like) – 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 aninitialization_vector
with a givenkey
.
- class cryptography.hazmat.primitives.ciphers.modes.CFB8(initialization_vector)[source]
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.
- Parameters:
initialization_vector (bytes-like) – 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 aninitialization_vector
with a givenkey
.
- class cryptography.hazmat.primitives.ciphers.modes.GCM(initialization_vector, tag=None, min_tag_length=16)[source]
Danger
If you are encrypting data that can fit into memory you should strongly consider using
AESGCM
instead of this.When using this mode you must not use the decrypted data until the appropriate finalization method (
finalize()
orfinalize_with_tag()
) has been called. GCM provides no guarantees of ciphertext integrity until decryption is complete.GCM (Galois Counter Mode) is a mode of operation for block ciphers. An AEAD (authenticated encryption with additional data) mode is a type of block cipher mode that simultaneously encrypts the message as well as authenticating it. Additional unencrypted data may also be authenticated. Additional means of verifying integrity such as HMAC are not necessary.
This mode does not require padding.
- Parameters:
initialization_vector (bytes-like) – Must be unique, a nonce. They do not need to be kept secret and they can be included in a transmitted message. NIST recommends a 96-bit IV length for performance critical situations but it can be up to 264 - 1 bits. Do not reuse an
initialization_vector
with a givenkey
.
Note
Cryptography will generate a 128-bit tag when finalizing encryption. You can shorten a tag by truncating it to the desired length but this is not recommended as it makes it easier to forge messages, and also potentially leaks the key (NIST SP-800-38D recommends 96-bits or greater). Applications wishing to allow truncation can pass the
min_tag_length
parameter.Changed in version 0.5: The
min_tag_length
parameter was added in0.5
, previously truncation down to4
bytes was always allowed.- Parameters:
tag (bytes) – The tag bytes to verify during decryption. When encrypting this must be
None
. When decrypting, it may beNone
if the tag is supplied on finalization usingfinalize_with_tag()
. Otherwise, the tag is mandatory.min_tag_length (int) – The minimum length
tag
must be. By default this is16
, meaning tag truncation is not allowed. Allowing tag truncation is strongly discouraged for most applications.
- Raises:
ValueError – This is raised if
len(tag) < min_tag_length
or theinitialization_vector
is too short.
An example of securely encrypting and decrypting data with
AES
in theGCM
mode looks like:import os from cryptography.hazmat.primitives.ciphers import ( Cipher, algorithms, modes ) def encrypt(key, plaintext, associated_data): # Generate a random 96-bit IV. iv = os.urandom(12) # Construct an AES-GCM Cipher object with the given key and a # randomly generated IV. encryptor = Cipher( algorithms.AES(key), modes.GCM(iv), ).encryptor() # associated_data will be authenticated but not encrypted, # it must also be passed in on decryption. encryptor.authenticate_additional_data(associated_data) # Encrypt the plaintext and get the associated ciphertext. # GCM does not require padding. ciphertext = encryptor.update(plaintext) + encryptor.finalize() return (iv, ciphertext, encryptor.tag) def decrypt(key, associated_data, iv, ciphertext, tag): # Construct a Cipher object, with the key, iv, and additionally the # GCM tag used for authenticating the message. decryptor = Cipher( algorithms.AES(key), modes.GCM(iv, tag), ).decryptor() # We put associated_data back in or the tag will fail to verify # when we finalize the decryptor. decryptor.authenticate_additional_data(associated_data) # Decryption gets us the authenticated plaintext. # If the tag does not match an InvalidTag exception will be raised. return decryptor.update(ciphertext) + decryptor.finalize() iv, ciphertext, tag = encrypt( key, b"a secret message!", b"authenticated but not encrypted payload" ) print(decrypt( key, b"authenticated but not encrypted payload", iv, ciphertext, tag ))
b'a secret message!'
- class cryptography.hazmat.primitives.ciphers.modes.XTS(tweak)[source]
Added in version 2.1.
Warning
XTS mode is meant for disk encryption and should not be used in other contexts.
cryptography
only supports XTS mode withAES
.Note
AES XTS keys are double length. This means that to do AES-128 encryption in XTS mode you need a 256-bit key. Similarly, AES-256 requires passing a 512-bit key. AES 192 is not supported in XTS mode.
XTS (XEX-based tweaked-codebook mode with ciphertext stealing) is a mode of operation for the AES block cipher that is used for disk encryption.
This mode does not require padding.
- Parameters:
tweak (bytes-like) – The tweak is a 16 byte value typically derived from something like the disk sector number. A given
(tweak, key)
pair should not be reused, although doing so is less catastrophic than in CTR mode.
Insecure modes
Warning
These modes are insecure. New applications should never make use of them, and existing applications should strongly consider migrating away.
- class cryptography.hazmat.primitives.ciphers.modes.ECB[source]
ECB (Electronic Code Book) is the simplest mode of operation for block ciphers. Each block of data is encrypted in the same way. This means identical plaintext blocks will always result in identical ciphertext blocks, which can leave significant patterns in the output.
Padding is required when using this mode.
Interfaces
- class cryptography.hazmat.primitives.ciphers.CipherContext[source]
When calling
encryptor()
ordecryptor()
on aCipher
object the result will conform to theCipherContext
interface. You can then callupdate(data)
with data until you have fed everything into the context. Once that is done callfinalize()
to finish the operation and obtain the remainder of the data.Block ciphers require that the plaintext or ciphertext always be a multiple of their block size. Because of that padding is sometimes required to make a message the correct size.
CipherContext
will not automatically apply any padding; you’ll need to add your own. For block ciphers the recommended padding isPKCS7
. If you are using a stream cipher mode (such asCTR
) you don’t have to worry about this.- update(data)[source]
- Parameters:
data (bytes-like) – The data you wish to pass into the context.
- Return bytes:
Returns the data that was encrypted or decrypted.
- Raises:
When the
Cipher
was constructed in a mode that turns it into a stream cipher (e.g.CTR
), this will return bytes immediately, however in other modes it will return chunks whose size is determined by the cipher’s block size.
- update_into(data, buf)[source]
Added in version 1.8.
Warning
This method allows you to avoid a memory copy by passing a writable buffer and reading the resulting data. You are responsible for correctly sizing the buffer and properly handling the data. This method should only be used when extremely high performance is a requirement and you will be making many small calls to
update_into
.- Parameters:
data (bytes-like) – The data you wish to pass into the context.
buf – A writable Python buffer that the data will be written into. This buffer should be
len(data) + n - 1
bytes wheren
is the block size (in bytes) of the cipher and mode combination.
- Return int:
Number of bytes written.
- Raises:
ValueError – This is raised if the supplied buffer is too small.
>>> import os >>> from cryptography.hazmat.primitives.ciphers import Cipher, algorithms, modes >>> key = os.urandom(32) >>> iv = os.urandom(16) >>> cipher = Cipher(algorithms.AES(key), modes.CBC(iv)) >>> encryptor = cipher.encryptor() >>> # the buffer needs to be at least len(data) + n - 1 where n is cipher/mode block size in bytes >>> buf = bytearray(31) >>> len_encrypted = encryptor.update_into(b"a secret message", buf) >>> # get the ciphertext from the buffer reading only the bytes written to it (len_encrypted) >>> ct = bytes(buf[:len_encrypted]) + encryptor.finalize() >>> decryptor = cipher.decryptor() >>> len_decrypted = decryptor.update_into(ct, buf) >>> # get the plaintext from the buffer reading only the bytes written (len_decrypted) >>> bytes(buf[:len_decrypted]) + decryptor.finalize() b'a secret message'
- finalize()[source]
- Return bytes:
Returns the remainder of the data.
- Raises:
ValueError – This is raised when the data provided isn’t a multiple of the algorithm’s block size.
Once
finalize
is called this object can no longer be used andupdate()
andfinalize()
will raise anAlreadyFinalized
exception.
- reset_nonce(nonce)[source]
Added in version 43.0.0.
This method allows changing the nonce for an already existing context. Normally the nonce is set when the context is created and internally incremented as data as passed. However, in some scenarios the same key is used repeatedly but the nonce changes non-sequentially (e.g.
QUIC
), which requires updating the context with the new nonce.This method only works for contexts using
ChaCha20
orCTR
mode.- Parameters:
nonce – The nonce to update the context with.
- Raises:
cryptography.exceptions.UnsupportedAlgorithm – If the algorithm does not support updating the nonce.
ValueError – If the nonce is not the correct length for the algorithm.
- class cryptography.hazmat.primitives.ciphers.AEADCipherContext[source]
When calling
encryptor
ordecryptor
on aCipher
object with an AEAD mode (e.g.GCM
) the result will conform to theAEADCipherContext
andCipherContext
interfaces. If it is an encryption or decryption context it will additionally be anAEADEncryptionContext
orAEADDecryptionContext
instance, respectively.AEADCipherContext
contains an additional methodauthenticate_additional_data()
for adding additional authenticated but unencrypted data (see note below). You should call this before calls toupdate
. When you are done callfinalize
to finish the operation.Note
In AEAD modes all data passed to
update()
will be both encrypted and authenticated. Do not pass encrypted data to theauthenticate_additional_data()
method. It is meant solely for additional data you may want to authenticate but leave unencrypted.- authenticate_additional_data(data)[source]
- Parameters:
data (bytes-like) – Any data you wish to authenticate but not encrypt.
- Raises:
- class cryptography.hazmat.primitives.ciphers.AEADEncryptionContext[source]
When creating an encryption context using
encryptor
on aCipher
object with an AEAD mode such asGCM
an object conforming to both theAEADEncryptionContext
andAEADCipherContext
interfaces will be returned. This interface provides one additional attributetag
.tag
can only be obtained afterfinalize
has been called.- tag
- Return bytes:
Returns the tag value as bytes.
- Raises:
NotYetFinalized
if called before the context is finalized.
- class cryptography.hazmat.primitives.ciphers.AEADDecryptionContext[source]
Added in version 1.9.
When creating an encryption context using
decryptor
on aCipher
object with an AEAD mode such asGCM
an object conforming to both theAEADDecryptionContext
andAEADCipherContext
interfaces will be returned. This interface provides one additional methodfinalize_with_tag()
that allows passing the authentication tag for validation after the ciphertext has been decrypted.- finalize_with_tag(tag)[source]
- Parameters:
tag (bytes) – The tag bytes to verify after decryption.
- Return bytes:
Returns the remainder of the data.
- Raises:
ValueError – This is raised when the data provided isn’t a multiple of the algorithm’s block size, if
min_tag_length
is less than 4, or iflen(tag) < min_tag_length
.min_tag_length
is an argument to theGCM
constructor.
If the authentication tag was not already supplied to the constructor of the
GCM
mode object, this method must be used instead offinalize()
.
- class cryptography.hazmat.primitives.ciphers.CipherAlgorithm[source]
A named symmetric encryption algorithm.
- class cryptography.hazmat.primitives.ciphers.BlockCipherAlgorithm[source]
A block cipher algorithm.
Interfaces used by the symmetric cipher modes described in Symmetric Encryption Modes.
- class cryptography.hazmat.primitives.ciphers.modes.Mode[source]
A named cipher mode.
- name
- Type:
This should be the standard shorthand name for the mode, for example Cipher-Block Chaining mode is “CBC”.
- validate_for_algorithm(algorithm)[source]
- Parameters:
algorithm (cryptography.hazmat.primitives.ciphers.CipherAlgorithm)
Checks that the combination of this mode with the provided algorithm meets any necessary invariants. This should raise an exception if they are not met.
For example, the
CBC
mode uses this method to check that the provided initialization vector’s length matches the block size of the algorithm.
- class cryptography.hazmat.primitives.ciphers.modes.ModeWithInitializationVector[source]
A cipher mode with an initialization vector.
- initialization_vector
- Type:
Exact requirements of the initialization are described by the documentation of individual modes.
- class cryptography.hazmat.primitives.ciphers.modes.ModeWithNonce[source]
A cipher mode with a nonce.
- nonce
- Type:
Exact requirements of the nonce are described by the documentation of individual modes.
- class cryptography.hazmat.primitives.ciphers.modes.ModeWithAuthenticationTag[source]
A cipher mode with an authentication tag.
- tag
- Type:
Exact requirements of the tag are described by the documentation of individual modes.