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SeedGuard HMAC

Hardens Paper and Spigot servers against practical world-seed leaks using per-player HMAC-derived fake seed hashes.
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SeedGuard-Forge-1.21.11-1.0.0.jar

File nameSeedGuard-Forge-1.21.11-1.0.0.jar
Uploader
ruaoptikalruaoptikal
Uploaded
Jul 13, 2026
Downloads
66
Size
1.9 MB
File ID
8422371
Type
R
Release
Supported game versions
  • 1.21.11
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What's new

SeedGuard 1.1.0 — Minecraft 1.21.11

- Rebuilt against the official Spigot 1.21.11 API using Java 21.
- Verified the 1.21.11 LOGIN and RESPAWN packet layout.
- Replaces the single seed field inside `CommonPlayerSpawnInfo` with a per-player HMAC-SHA256 value.
- Added a safe temporary-player fallback for the initial login packet.
- Refuses to enable on Minecraft versions other than 1.21.11.
- Refuses to enable with ProtocolLib 5.4.0, which does not officially support 1.21.11.
- Defaults to fail-closed behavior so an incompatible packet is never sent with the real seed hash.
- Requires the current official ProtocolLib development build with 1.21.11 support, or ProtocolLib 5.4.1+.
- Blocks `/seed`, `/locate`, and namespaced variants for players without bypass permission.
- Does not modify blocks, chunks, biomes, structures, loot, or world generation.

This mod has no additional files