Public Key Server - Secure File Transfer with SurePack

🔐 How the Public Key Server Works

The Public Key Server is the backbone of secure, decentralized file sharing using post-quantum cryptography. Here's how it enables secure communication:

Key Components

🔑

Alias Registration

Users create unique aliases (identities) with quantum-resistant key pairs. Public keys are stored on the server, private keys remain with users.

📡

Key Distribution

The server acts as a trusted directory, allowing users to look up public keys by alias name for encryption.

📦

Package Routing

Encrypted packages are temporarily stored on the server and routed to recipients without the server accessing content.

🛡️

Zero-Knowledge

The server never sees private keys or decrypted content. All encryption/decryption happens client-side.

The Process Flow

Alias Creation: User generates a quantum-resistant key pair locally
Registration: Public key and alias are registered with the server
Lookup: Sender queries server for recipient's public key
Encryption: Files are encrypted locally using recipient's public key
Upload: Encrypted package is uploaded to server
Notification: Server notifies recipient (if email provided)
Download: Recipient retrieves encrypted package
Decryption: Package is decrypted locally with private key

Privacy & Security Features

Anonymous Option: Create aliases without email or personal information
Quantum-Resistant: Uses CRYSTALS-Dilithium and CRYSTALS-Kyber algorithms
End-to-End Encryption: Server cannot decrypt packages
Temporary Storage: Packages are automatically deleted after retrieval or timeout
Certificate Pinning: Prevents man-in-the-middle attacks

📥 Download SurePack

SurePack is available for all major platforms. Choose your version:

macOS (Intel x64)
surepack

macOS (Apple Silicon)
surepack

Windows (64-bit)
surepack.exe

Windows (32-bit)
surepack.exe

Windows (ARM64)
surepack.exe

Linux (x64)
surepack

Linux (ARM64)
surepack

Linux (ARM/Raspberry Pi)
surepack

Note: On macOS and Linux, you may need to make the file executable: chmod +x surepack

🚀 Quick Start Guide

Two Simple Steps to Get Started

1 Create Your Identity (Alias)

surepack create

2 Send a File

surepack pack -i myfile.pdf -a recipient-alias -f your-alias -o package.surepack
surepack send -i package.surepack

That's it! Your file is now securely encrypted and sent.

📖 SurePack User Manual

What is SurePack?

SurePack is a secure file transfer application that uses military-grade encryption with post-quantum cryptography. It allows you to send files securely and optionally anonymously to other users. Think of it as "PGP for 2025" - but much easier to use!

🔐

End-to-End Encryption

Only recipients can decrypt your files

🛡️

Quantum-Resistant

Protected against future quantum computers

🎭

Anonymous Option

No email or identity required

🚀

Easy to Use

Simple commands or GUI interface

Creating Your Alias (Digital Identity)

An alias is your unique identity in the SurePack system. It's like a secure email address that you'll use to send and receive files.

Command Line Method

surepack create

You'll be prompted to enter a password to protect your private keys. Choose a strong password and remember it!

GUI Method

surepack gui

Then navigate to: Manage Aliases → Create New Alias

Optional: Associate an Email

If you want to be identifiable (not anonymous), you can associate an email:

# Step 1: Request verification code
surepack verify -e yourname@example.com

# Step 2: Create alias with verification code
surepack create -e yourname@example.com -t 123456

Sending Files

Step 1: Pack Your Files

surepack pack -i "document.pdf" -a "recipient-alias" -f "your-alias" -o "package.surepack"

For multiple files:

surepack pack -i "file1.doc,file2.pdf,file3.jpg" -a "recipient" -f "sender" -o "package.surepack"

For a whole folder:

surepack pack -i "C:\MyFolder" -a "recipient" -f "sender" -o "package.surepack"

Step 2: Send the Package

surepack send -i "package.surepack"

Tip: You can combine pack and send in one command:

surepack pack -i "file.pdf" -a "recipient" -f "sender" -o "pkg.surepack" && surepack send -i "pkg.surepack"

Receiving Files

Step 1: Check for Packages

surepack receive -a "your-alias"

Step 2: Unpack the Files

surepack unpack -i "received-package.surepack" -o "output-folder"

Command Reference

Command	Description
`surepack create`	Create a new alias
`surepack verify -e email`	Request email verification code
`surepack list`	Show your aliases
`surepack pack`	Create encrypted package
`surepack send`	Upload package to server
`surepack receive`	Download packages
`surepack unpack`	Decrypt and extract files
`surepack gui`	Launch graphical interface

🔒 Security Information

Where Your Keys Are Stored

Windows: %LOCALAPPDATA%\surepack
macOS: ~/Library/Application Support/surepack
Linux: ~/.local/share/surepack

Important: Your private keys are stored encrypted with your password. Never share your private key files or password with anyone!

Best Practices

Use a strong, unique password for your alias
Back up your key files in a secure location
Verify recipient aliases before sending sensitive files
For maximum anonymity, don't associate an email with your alias
Regularly check for software updates

Technical Details

SurePack uses the following cryptographic algorithms:

Digital Signatures: CRYSTALS-Dilithium (NIST PQC standard)
Key Encapsulation: CRYSTALS-Kyber (NIST PQC standard)
Symmetric Encryption: AES-256-GCM
Key Derivation: Argon2id

💻 Open Source

The Public Key Server and SurePack are open source projects. View the source code, contribute, or report issues on GitHub.

Help Center View Source Code Report Issues Documentation Contribute

publickeyserver.org

🔐 Root Certificate Authority Signature