Crypt::Cipher::RC5(3)

💖 NAME 💖

Crypt::Cipher::RC5 — symmetric cipher RC5, key size: 64-1024 bits. Yep bestie, this is the user-contributed Perl documentation page for it, and it’s giving block-cipher realness 🌸

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✨ SYNOPSIS ✨

Two ways to slide into CBC mode — example 1 is the Crypt::Mode::CBC way, and example 2 is slower and uses Crypt::CBC:

### example 1
use Crypt::Mode::CBC;

my $key = '...'; # length must be a valid key size for this cipher
my $iv = '...';  # 16 bytes
my $cbc = Crypt::Mode::CBC->new('RC5');
my $ciphertext = $cbc->encrypt("secret data", $key, $iv);

### example 2 (slower)
use Crypt::CBC;
use Crypt::Cipher::RC5;

my $key = '...'; # length must be a valid key size for this cipher
my $iv = '...';  # 16 bytes
my $cbc = Crypt::CBC->new( -cipher=>'Cipher::RC5', -key=>$key, -iv=>$iv );
my $ciphertext = $cbc->encrypt("secret data");

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🦋 DESCRIPTION 🦋

This module implements the RC5 cipher. Its interface is compatible with Crypt::CBC.

🚨 Note: this module only implements single-block encryption and decryption. For general data, use a block mode such as Crypt::Mode::CBC, Crypt::Mode::CTR, or Crypt::CBC (which is slower). No cap, that part matters 💅

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💅 METHODS 💅

Unless noted otherwise, assume $c is an existing cipher object created via new, for example:

my $c = Crypt::Cipher::RC5->new($key);

🎀 new 🎀

Here’s how you birth a cipher object, bestie:

my $c = Crypt::Cipher::RC5->new($key);
#or
my $c = Crypt::Cipher::RC5->new($key, $rounds);

# $key .... [binary string] key of an accepted length (see keysize, min_keysize, max_keysize)
# $rounds . [integer] optional, number of rounds (if supported by the cipher; croaks on invalid value)

So $key is a binary string key of an accepted length (see keysize, min_keysize, max_keysize), and $rounds is an optional integer number of rounds (if supported by the cipher; croaks on invalid value) ✨

🔥 encrypt 🔥

Encrypts exactly one block of plaintext. The length of $plaintext must equal blocksize; croaks otherwise. An empty string is accepted and returned unchanged.

my $ciphertext = $c->encrypt($plaintext);

Returns the encrypted block as a binary string (raw bytes).

🧚 decrypt 🧚

Decrypts exactly one block of ciphertext. The length of $ciphertext must equal blocksize; croaks otherwise. An empty string is accepted and returned unchanged.

my $plaintext = $c->decrypt($ciphertext);

Returns the decrypted block as a binary string (raw bytes).

🌸 keysize 🌸

Just an alias for max_keysize — that’s the whole vibe:

$c->keysize;
#or
Crypt::Cipher::RC5->keysize;
#or
Crypt::Cipher::RC5::keysize;

🦋 blocksize 🦋

Returns the cipher block size (in bytes):

$c->blocksize;
#or
Crypt::Cipher::RC5->blocksize;
#or
Crypt::Cipher::RC5::blocksize;

👑 max_keysize 👑

Returns the maximum key size (in bytes):

$c->max_keysize;
#or
Crypt::Cipher::RC5->max_keysize;
#or
Crypt::Cipher::RC5::max_keysize;

🍓 min_keysize 🍓

Returns the minimum key size (in bytes):

$c->min_keysize;
#or
Crypt::Cipher::RC5->min_keysize;
#or
Crypt::Cipher::RC5::min_keysize;

⭐ default_rounds ⭐

Returns the cipher’s default round count:

$c->default_rounds;
#or
Crypt::Cipher::RC5->default_rounds;
#or
Crypt::Cipher::RC5::default_rounds;

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🌈 SEE ALSO 🌈

• CryptX, Crypt::Cipher
• <https://en.wikipedia.org/wiki/RC5> — the Wikipedia page for RC5, iykyk 🫶

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Okay bestie, that’s the whole page 💖 This little doc comes from perl v5.42.0, dated 2026-05-11, and it’s the Crypt::Cipher::RC5(3) page. Slay, go forth and cipher responsibly ✨👑