Sigil is a security-focused Forge mod that adds cryptographic access control to Minecraft servers. Instead of relying solely on vanilla UUID checks, Sigil requires players to authenticate using server-signed Ed25519 certificates during login.
Sigil supports both online-mode servers (certificates bound to Mojang UUIDs) and offline-mode servers (certificates bound to cryptographic keypairs), allowing private, LAN, or invite-only servers to enforce strong identity guarantees.
Each server has a deterministic identity derived from its signing key, and clients pin the server fingerprint to prevent man-in-the-middle attacks or credential leakage. Certificates can be time-limited, revoked instantly, and distributed through ready-to-use admin bundles.
Sigil is designed for server operators who want explicit control over who may connect, without turning Minecraft into an account system or permissions mod.
For information on utilizing this mod please visit the main repository page
To report any bugs or issues please create an issue on the offical issues page
Sigil enforces access control - not anti-cheat or gameplay rules.
- Edition: Minecraft Java
- File type: .jar
- Minecraft version listed: 1.20.1
- How to install: Install the matching mod loader (Forge, Fabric or NeoForge) for your Minecraft version. → Download the .jar. → Put it in the .minecraft/mods folder and launch that loader profile.
- Where to get it: Opens on Modrinth — not every file is mirrored on our own servers.
Install steps are the general flow for this file type — How to install Minecraft Java mods & modpacks walks through it step by step.
- Ships as sigilmod-forge-1.0.jar — drop this file into the mods folder
- Download size: 55 KB
- Download link checked 11 Sept 2026 — working
These come from our own check of the pack file, not from the source page.