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Integrity Check: VerifySignatures

By default, the Arma 3 engine is highly trusting of connected clients. To prevent malicious actors from joining your server with modified .pbo files (such as “One Hit Kill” weapon modifications or “Transparent Walls” foliage mods), you must enforce strict signature verification. This system ensures that every file on the player’s computer is a bit-for-bit match with the official files signed by the mod developers.

Difficulty

Intermediate

Time

5 Minutes

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Enabling Enforcement

To activate signature checking, you must modify your server.cfg file.
1

Open server.cfg

In the Game Panel File Manager, locate and open your server.cfg.
2

Set Verification Level

Find the verifySignatures property and set its value to 2.
verifySignatures = 2;
Verification is off. Anyone can join with any modified files. This is a severe security risk for public servers.

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The Key System: Managing .bikey Files

For a mod to pass the V2 check, your server must possess its Public Key (.bikey).
1

Locate the Mod Key

Open the mod folder on your local PC (e.g., @ACE3). Look for a sub-folder named keys or serverkeys.
2

Extract the .bikey

Find the public key file inside (e.g., ace3.bikey).
3

Upload to Server

Use the File Manager or SFTP to upload this file to the root /keys/ directory on your FREAKHOSTING game server.
Result: Your server now “Trusts” any .pbo file that has been signed by the owner of that specific key.
If players are kicked immediately upon joining with a “Signature Mismatch” or “File not signed by a key accepted by this server” error, check the following:
  • Missing Key: You likely forgot to upload the .bikey file for one of the mods running on your server.
  • Outdated Mod: The player’s local mod files may be outdated or corrupt. Instruct them to use the “Repair Mod” or “Verify Integrity” feature in the Arma 3 Launcher.
  • Server Version: Ensure the server’s mod files are up to date via the Game Panel’s Steam Workshop manager.

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Need Extra Help?

If you encounter any issues, our support team is ready to assist:

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Last Updated: January 2026 | Arma 3: Perimeter secured.