Benjamin Trott
and 1 contributors


Digest::BubbleBabble - Create bubble-babble fingerprints


    # Create a fingerprint of a simple string.
    use Digest::BubbleBabble qw( bubblebabble );
    my $fingerprint = bubblebabble( Digest => "Pineapple" );

    # Create a fingerprint of a SHA-1 hash.
    use Digest::SHA1 qw( sha1 );
    $fingerprint = bubblebabble( Digest => sha1("hello") );


Digest::BubbleBabble takes a message digest (often generated by either of the MD5 or SHA-1 message digest algorithms) and creates a fingerprint of that digest in "bubble babble" format. Bubble babble is a method of representing a message digest as a string of "real" words, to make the fingerprint easier to remember. The "words" are not necessarily real words, but they look more like words than a string of hex characters.

Bubble babble fingerprinting is used by the SSH2 suite (and, consequently, by Net::SSH::Perl, the Perl SSH implementation) to display easy-to-remember key fingerprints. The key (a DSA or RSA key) is converted into a textual form, digested using Digest::SHA1, and run through bubblebabble to create the key fingerprint.


Digest::BubbleBabble conditionally exports one function called bubblebabble; to import the function you must choose to import it, like this:

    use Digest::BubbleBabble qw( bubblebabble );

bubblebabble( Digest => $digest )

Currently takes only one pair of arguments, the key of which must be Digest, the value of which is the actual message digest $digest. You should generate this message digest yourself using either Digest::MD5 of Digest::SHA1.

Returns the bubble babble form of the digest.


The BubbleBabble specification is available at:


Digest::BubbleBabble is free software; you may redistribute it and/or modify it under the same terms as Perl itself.


Benjamin Trott,

Except where otherwise noted, Digest::BubbleBabble is Copyright 2001 Benjamin Trott. All rights reserved.