blowssi is a an irssi cryptography script.

Key features

  • Compatible with mircryption and FiSH.
  • Supports both cbc and ecb encryption modes. (to use cbc encryption just prefix the key with cbc: )
  • Blowssi is Free (both as in freedom and as in beer) software (licensed under the GNU GPL v3)
  • Blowssi will work on any platform perl and irssi work on.
  • dh1080 key exchange (since 0.2.0)


  • perl
  • Crypt::ircBlowfish (see bundeled zip file, but also available from
  • Crypt::ircDH1080 (see bundled tar.gz file - if you have problems with Math::Pari or Crypt::Random, see alternative module in the download page.)
  • Crypt::CBC (on gentoo you can just: emerge dev-perl/crypt-cbc)
  • MIME:Base64 (on gentoo you can just: emerge perl-MIME-Base64 (which is a virtual package) or emerge perl-core/MIME-Base64 though you probably already have it.)
  • irssi ;)


  • First make sure all requirements are installed (see above).
  • To install, just put the script in ~/.irssi/scripts and put this in your ~/.irssi/startup :
                 /load ~/.irssi/scripts/


  • /blowon : Turns encryption back on after you used /blowoff (it's on by default) note that blowssi will not attempt to encrypt/decrypt in channels without key anyway. This is just for convenience in case you don't want to use the backtick (`) method. (see notes)
  • /blowoff : Causes encryption and decryption to be skipped for all channels, even with key.
  • /blowkey channel key : sets a key for a channel or nickname (for pm queries)
                 eg: /blowkey #mircryption test
                     /blowkey Gothi[c] foo
    Note that you must use the # character for channels.
  • /blowdel channel : Removes a key for a channel or nickname (query), effectively disabeling encryption.
  • /blowkeyx cbc|ecb user : Starts a key exchange with specified user, using specified mode (ecb or cbc).


  • If you start a line with a backtick (`), encryption will be bypassed.
  • Prefix a key with cbc: to use CBC mode instead of ECB.
  • Use # for channels, or nicknames to set keys for query windows.


  • Configuration file is stored in ~/.irssi/blowssi.conf
    Syntax is