Crypt::AuthEnc::SIV(3) User Contributed Perl Documentation
NAME
Crypt::AuthEnc::SIV - Authenticated encryption in SIV mode
SYNOPSIS
use Crypt::AuthEnc::SIV qw( siv_encrypt_authenticate siv_decrypt_verify );
my $ciphertext = siv_encrypt_authenticate('AES', $key, $plaintext);
my $ciphertext = siv_encrypt_authenticate('AES', $key, $plaintext, $adata);
my $ciphertext = siv_encrypt_authenticate('AES', $key, $plaintext, [$ad1, $ad2, ...]);
my $plaintext = siv_decrypt_verify('AES', $key, $ciphertext);
my $plaintext = siv_decrypt_verify('AES', $key, $ciphertext, $adata);
my $plaintext = siv_decrypt_verify('AES', $key, $ciphertext, [$ad1, $ad2, ...]); # undef on failure
DESCRIPTION
Since: CryptX-0.089
SIV (Synthetic IV) is a deterministic authenticated encryption scheme
defined in RFC 5297 <https://www.rfc-editor.org/rfc/rfc5297>. Unlike
nonce-based modes, SIV derives the authentication tag (the IV)
synthetically from the key, associated data, and plaintext, making it
nonce-misuse resistant.
The output of "siv_encrypt_authenticate" is the 16-byte SIV tag
prepended to the ciphertext (total output length is "length($plaintext)
+ 16").
BEWARE: SIV requires a key that is twice the length of the underlying
cipher key (e.g. 256 bits for AES-128-SIV, 512 bits for AES-256-SIV).
If you pass associated data as an arrayref, at most 126 components are
accepted.
EXPORT
Nothing is exported by default.
You can export selected functions:
use Crypt::AuthEnc::SIV qw( siv_encrypt_authenticate siv_decrypt_verify );
FUNCTIONS
siv_encrypt_authenticate
my $ciphertext = siv_encrypt_authenticate($cipher, $key, $plaintext);
#or
my $ciphertext = siv_encrypt_authenticate($cipher, $key, $plaintext, $adata);
#or
my $ciphertext = siv_encrypt_authenticate($cipher, $key, $plaintext, [$ad1, $ad2, ...]);
# $cipher ... [string] cipher name (e.g. 'AES')
# $key ... [binary string] key (must be double the cipher's standard key length)
# $plaintext ... [binary string] plaintext to encrypt
# $adata ... [binary string | arrayref] optional associated data: a scalar string or an arrayref of up to 126 string/buffer scalars
Returns a string of "length($plaintext) + 16" bytes (16-byte SIV tag
prepended to ciphertext).
The required $key and $plaintext arguments must be string/buffer
scalars. If $adata is given as a scalar, it must also be a
string/buffer scalar. If it is given as an arrayref, each defined
element must be a string/buffer scalar. String-overloaded objects are
accepted.
siv_decrypt_verify
my $plaintext = siv_decrypt_verify($cipher, $key, $ciphertext);
#or
my $plaintext = siv_decrypt_verify($cipher, $key, $ciphertext, $adata);
#or
my $plaintext = siv_decrypt_verify($cipher, $key, $ciphertext, [$ad1, $ad2, ...]);
# $cipher ... [string] cipher name (e.g. 'AES')
# $key ... [binary string] key (must be double the cipher's standard key length)
# $ciphertext ... [binary string] ciphertext with 16-byte SIV tag prepended
# $adata ... [binary string | arrayref] optional associated data: a scalar string or an arrayref of up to 126 string/buffer scalars
Returns the plaintext on success, or "undef" if authentication fails.
Malformed ciphertext shorter than 16 bytes croaks because it cannot
contain the required prepended SIV tag.
The required $key and $ciphertext arguments must be string/buffer
scalars. If $adata is given as a scalar, it must also be a
string/buffer scalar. If it is given as an arrayref, each defined
element must be a string/buffer scalar. String-overloaded objects are
accepted.
SEE ALSO
o CryptX(3), Crypt::AuthEnc::EAX(3), Crypt::AuthEnc::GCM(3)
o RFC 5297 <https://www.rfc-editor.org/rfc/rfc5297>
perl v5.34.3 2026-05-11 Crypt::AuthEnc::SIV(3)
cryptx 0.89.0 - Generated Tue May 12 14:13:04 CDT 2026