Here's a little passion project I've been working on! 1. Concept and Onboarding SimplePGP is more than just a messaging platform; it is infrastructure for private, end-to-end communication that does not require trusting a platform with your message contents. It is based on OpenPGP encryption so only the people in a conversation can read what is sent. Users create an account by generating a PGP keypair directly on their mobile device. The public key becomes their identity, so anyone can verify it's them and no one can impersonate them without the key. Identity is tied to cryptography rather than a company's user database. 2. How it works Messages are encrypted on the client (Android or web) before they leave the device, sealed to the recipient's public key and wrapped again in TLS for transit. They are then relayed through a server that routes armored ciphertext during delivery. The server never has access to plaintext and never holds a private key. Direct messages, group chats, and public "nodes" (IRC-style channels) all share the same encrypted messaging model, alongside peer-to-peer voice and video calls where the server handles signaling only and the media flows directly between devices. Unlocking the private key takes more than a password. At signup, the password and a biometric-gated secret are each stretched through salted PBKDF2-SHA256 (200,000 iterations) and XOR-combined into a single 256-bit shard that protects the key. Meaning, neither factor alone gets an attacker anywhere. Optional browser access is linked from the phone via QR login: the phone and browser perform an ECDH handshake, and the phone hands over the key vault AES-GCM-wrapped and bound to that specific browser tab, so the web session can use the same keys without pasting secrets into a form. In the browser, keys live in memory only and vanish when the session ends. Alongside messaging, SimplePGP includes a lightweight economy layer: SPGP balance, inventory, and a trade desk with real cryptocurrency deposit invoices. Bitcoin is already implemented end to end (one-time deposit addresses with on-chain payment verification), with USDT, ETH, XMR, and other cryptocurrencies in active development. This lets users exchange value and items with people they already talk to, still under their own account control.

If you're building a Mini App (or thinking about it), there’s now a weekly call where you can get answers, unblock yourself, and connect directly with other builders and the competition team. It's called Sip & Ship, with the first session happening on Wednesday, July 8 at 11:00 AM ET. Read our X article for all the details! 🔗 https://x.com/miniappscomp/status/2073137904722063861?s=20