s!mpL3

s!mpL3 LAN Messenger 3.1.0.0

Released 22/10/2026

  1. Stronger encryption. Messages between computers running 3.1 are now encrypted with AES-256, and every message carries a tamper check, so changed, forged or replayed messages are ignored. Computers running older versions can still talk to 3.1 as before. Note: the clocks of the computers must be within 10 minutes of each other.
  2. Encrypted file transfers. Files sent between computers running 3.1 are encrypted with a one-time key for each transfer, and the receiving computer has to prove it has that key before anything is sent. Resuming an interrupted transfer still works.
  3. Fixed a security problem where another computer on the network could ask yours for any file. Your computer now only sends the files you actually offered, and only to the person you offered them to.
  4. Received file names are checked, so a file can never be saved outside your download folder or under a reserved Windows name.
  5. Fixed a security problem in calls: a call partner could pretend you had allowed remote control. Remote control now always needs you to click Allow.
  6. Signed updates. Every update, online or from another computer on the LAN, now has to carry the s!mpL3 digital signature before it is installed.
  7. Fixed a crash ("Variable used without being declared") when updating from the About window. If you are on 2.9.9.1 or 3.0.0.0, update using the automatic check at start-up (Edit->Preferences, "Check for updates on startup") or download 3.1 from the website.
  8. The network passphrase can now be up to 64 characters long (it was 10). If you still use the built-in default passphrase, s!mpL3 reminds you to set your own. Use the same passphrase on every computer that should talk to each other.
  9. Passwords are stored more safely. The network passphrase is now protected by Windows for your user account, and the lock password is only stored as a one-way hash. Your existing settings are converted automatically.
  10. Fixed the lock password being removed when Preferences were saved without opening the password box.
  11. Messages waiting for someone who is offline are now stored with a random encryption key.
  12. Links in conversations now only open web pages and e-mail addresses.
  13. Fixed damaged or unexpected network messages being able to close the program.
  14. Other small fixes.