Encryption

Modpack download connection is secured using TLS 1.3.

This is the same security standard used by HTTPS, the protocol which you're using all the time to browse the web (even now!).

TLS has method of verifying the server's identity using a certificate which is crucial to prevent attacks such as Man-in-the-middle.

That's why AutoModpack requires you to verify the server's certificate fingerprint when connecting to the server for the first time. Read how to verify the certificate fingerprint for more details.

Direct Downloads

AutoModpack uses direct download links from Modrinth and CurseForge APIs to download most of your modpack files. This means that the mod authors get credit for every download.

However if file you are providing in the modpack is not available on Modrinth or CurseForge, AutoModpack will download it (also directly) but from your server.

Compression

To speed up the download, AutoModpack compresses the modpack files using Zstandard compression algorithm. This algorithm is very fast and provides great compression ratio, which means that the modpack files are smaller and faster to download. This is especially useful for larger modpacks or slower internet connections. However this only applies to files downloaded from your server.

Authorization

AutoModpack uses a simple authorization mechanism to prevent unauthorized access to your modpack. When you connect to the server, in the background AutoModpack generates a random unique secret for each player. This secret is then send to the player and used to authorize the player to download the modpack files. Every time you reconnect to the server, the old secret is invalidated and a new one is generated. This prevents unauthorized access to your modpack files and ensures that only whitelisted and not banned players can download the modpack. If you don't want to use this feature, you can disable it (validateSecrets) in the server config.