Mladen Milankovic

mmlado - walleteer. Air-gapped wallets that do not phone home.

Freelance engineer. Author of Keycard Pal, an air-gapped wallet for Status Keycard on Google Play, the App Store and F-Droid, and of the keycard-py and keycard-nim SDKs. Contributed two instructions to the Status Keycard JavaCard applet: GET CHALLENGE and an ECDH key-agreement instruction (both released in applet 4.0). Built the hardware wallet QR signing in the Status wallet. Delivered two Rust RFP libraries for Logos spel.

Independent, open to work in the privacy space.

I believe sovereignty begins the moment someone realizes: you don't have to accept the default.

Writing

• Keycards for a building nobody can renovate, September 2026
• Code Against the Machine, June 2025
• Keycards for a Building Nobody Can Renovate, printed in the Logos zine Local Area Network 02 (p. 10), October 2026

Building on Keycard

• Keycard Pal - air-gapped wallet, Android and iOS: Google Play, App Store, F-Droid (reproducible builds); listed on keycard.tech/wallets
• ERC-4527 hardware wallet QR signing for the Status wallet, merged upstream into status-im/status-web, built on qrkit
• Three merged PRs in the Status Keycard applet: GET CHALLENGE, ECDH key agreement (both in applet 4.0) and a SELECT response fix
• keycard-nostr-bunker - NIP-46 remote signer that keeps the Nostr key on the card
• SDKs: keycard-py, used by Keycard's own firmware signing tool; keycard-nim; merged PRs to keycard-sdk and react-native-keycard

Building on Logos

• spel-admin-authority - Admin Authority library for Logos spel (RFP-001, won and delivered)
• spel-freeze-authority - Freeze Authority library for Logos spel (RFP-002, won and delivered)
• Built the SPEL extension mechanism and the multi-signature witness exchange, merged upstream into the Logos spel framework
• Wrote the Extensions section of the Logos docs
• Two Logos Lambda Prizes: Keycard NIP-46 Nostr signer (repo) and Shell dApp integration proof of concept (live demo)

Talks

Your Keys Never Leave the Card (Except Once): Hands-On Air-Gapped Signing

Dark Prague 2026, hands-on workshop in the Logos Attic - no recording

Code Against the Machine: Cypherpunks, technoanarchists & post-state futures

EthBelgrade 2025

Dev Tooling track

EthBelgrade 2024 - no recording (venue technical difficulties)

Smart Contract Development with Vyper

EthBelgrade 2023

Tehnički aspekti blokčejna

Serbian Academy of Sciences, 2022

Elsewhere

• GitHub
• LinkedIn
• X
• Older posts (Paragraph)
• Digital Self-Defense on YouTube: Serbian / Hungarian