# SeedGuard<\/p>\n
**SeedGuard** is a security plugin for **Paper 1.21.11** that helps protect SMP servers from common methods used to obtain the world seed.<\/p>\n
The plugin is designed for server owners who want to significantly increase the difficulty of seed extraction by players using seed-cracker mods, exploits, packet-based methods, and technical abuse of structure\/NBT mechanics.<\/p>\n
## About the plugin<\/p>\n
SeedGuard **does not promise absolute mathematical impossibility** of recovering the seed in every theoretical scenario.<\/p>\n
Instead, it blocks and complicates the most common and practical seed leak paths on multiplayer servers.<\/p>\n
## Features<\/p>\n
### 1. Fake seed
\nThe plugin intercepts important outgoing packets and replaces the real `hashed seed` with a fake value.<\/p>\n
Protection is applied in key scenarios:
\n– joining the server
\n– respawning \/ state changes where the client receives world data again<\/p>\n
This makes it harder for client-side mods and tools to read the real seed directly from network data.<\/p>\n
### 2. Command blocking
\nThe plugin blocks:
\n– `\/seed`
\n– `\/minecraft:seed`
\n– `\/bukkit:seed`
\n– `\/spigot:seed`
\n– `\/paper:seed`<\/p>\n
### 3. Command hiding
\nBlocked commands are removed from:
\n– the list of available commands
\n– tab-completion suggestions
\n– command suggestions where possible<\/p>\n
### 4. Structure and Jigsaw
\nThe plugin can block:
\n– `placing structure blocks`
\n– `breaking structure blocks`
\n– `interacting with structure blocks`
\n– `placing jigsaw blocks`
\n– `breaking jigsaw blocks`
\n– `using jigsaw-related functionality`<\/p>\n
### 5. Packet protection
\nSeedGuard blocks technical packets related to:
\n– `block\/entity NBT queries`
\n– `structure update\/generate`
\n– `jigsaw update`
\n– `debug subscription-like requests`<\/p>\n
### 6. Fake seed modes
\nThe following modes are supported:
\n– `per_player_stable` \u2014 a stable fake seed for each player
\n– `random_each_join` \u2014 a new fake seed on every join
\n– `fixed` \u2014 the same configured fake seed for everyone<\/p>\n
## Recommended mode<\/p>\n
For most SMP servers, it is recommended to use:<\/p>\n
“`yml
\nfake-seed:
\n mode: “per_player_stable”
\n““<\/p>\n
## Configuration<\/p>\n
The plugin allows you to individually enable or disable:<\/p>\n
* join packet protection
\n* respawn packet protection
\n* structure packet blocking
\n* jigsaw packet blocking
\n* NBT query packet blocking
\n* debug packet blocking
\n* command list updating on player join
\n* console logging of blocked attempts<\/p>\n
## Permission<\/p>\n
`seedguard.bypass`<\/p>\n
Players with this permission bypass the plugin\u2019s restrictions.<\/p>\n
## Compatibility<\/p>\n
* **Server:** Paper
\n* **Minecraft version:** 1.21.11
\n* **Java:** 21 recommended<\/p>\n
## Important<\/p>\n
SeedGuard is a **hardening plugin**, not a \u201cmagic button\u201d.
\nIt is designed to make real-world seed leak methods much less convenient and to block the most common practical seed leak paths on SMP servers.<\/p>\n
## Installation<\/p>\n
1. Download the latest version
\n2. Move the `.jar` file into the `plugins` folder
\n3. Start or restart the server
\n4. Configure `config.yml` if needed
\n5. Make sure to replace the default `salt` with your own long random string<\/p>\n
## Recommendations<\/p>\n
* Use **Paper 1.21.11**
\n* Use **Java 21**
\n* Replace the default salt in the config before using the plugin on a live server<\/p>\n
## Why use SeedGuard<\/p>\n
**SeedGuard is a good choice if you want to:**<\/p>\n
* make seed-cracker mods less effective
\n* close easy seed leak paths
\n* improve the security of a public or private SMP
\n* limit technical abuse related to structure\/NBT packet paths<\/p>\n","protected":false},"excerpt":{"rendered":"
Security plugin for Paper 1.21.11 that makes world-seed leaks much harder by replacing hashed seed data and blocking common leak paths.<\/p>\n","protected":false},"featured_media":136934,"template":"","meta":{"_minecraft_slug":"seedguard-by-meldix","_minecraft_project_id":"RmmbTbwu","_minecraft_author":"Meldix","_minecraft_license":"MIT","_minecraft_downloads":21,"_minecraft_follows":0,"_minecraft_client_side":"unsupported","_minecraft_server_side":"required","_minecraft_storage_type":"zip","_minecraft_archive_name":"seedguard-by-meldix.zip","_minecraft_size_bytes":4505212,"_minecraft_version_count":1,"_minecraft_updated_at":"2026-05-15T22:27:49.025899Z","_minecraft_date_created":"2026-04-28T20:19:47.872732Z","_minecraft_date_modified":"2026-04-10T20:40:40.583953Z","_minecraft_project_url":"https:\/\/modrinth.com\/mod\/seedguard-by-meldix","_minecraft_icon_attachment_id":136934,"_minecraft_imported_at":"2026-06-08T02:10:58+00:00","_minecraft_import_hash":"fac0e63bc0dbddc039061f8fa69a04e1","_minecraft_versions":"","_minecraft_links":"","_minecraft_gallery":"","_minecraft_api_metadata":""},"mod_category":[126,127,123,92],"mod_loader":[132],"minecraft_version":[41],"class_list":["post-136933","mod","type-mod","status-publish","has-post-thumbnail","hentry","mod_category-management","mod_category-paper","mod_category-technology","mod_category-utility","mod_loader-paper","minecraft_version-1-21-11"],"yoast_head":"\n