W2QR

W2QR Cards

Pre-printed physical or digital cards with QR codes that become crypto wallets when activated.

What are W2QR Cards?

A W2QR Card is a physical card (or digital equivalent) that carries a pre-printed QR code. The QR code contains random data that, through honey encryption, becomes a real cryptocurrency wallet when you activate it with your password.

The key property: any password produces a valid wallet. The password you choose during activation determines which wallet the card creates. An attacker who obtains your card cannot determine which wallet it “really” holds without your password.

Creating a Card

  1. Go to Create Card
  2. Choose a design template: Midnight (default), Ocean, Emerald, Graphite, or Light
  3. Add a nickname and optional wallet code
  4. Click Create Card to generate the QR code
  5. Print the card or save the digital image

Cards follow the CR80/ID-1 standard (85.60 × 53.98 mm) — the same size as a credit card.

Activating a Card

  1. Go to Activate Card and scan or upload the card's QR code
  2. Choose a strong password — this password, combined with the card's QR data, creates your unique wallet
  3. Save your recovery phrase (12 BIP-39 words)
  4. Use the Strong Password Generator for maximum protection — derive a quantum-resistant password from a memorable phrase in your native language and store it as a password QR. Optionally back up the wallet QR to Google Drive.

Security Properties

  • ✓No password oracle — every password produces a valid wallet. There is no way to tell if a password is “correct” without checking the resulting wallet on the blockchain.
  • ✓Plausible deniability — if someone obtains your card, they cannot prove which wallet it holds. Any password they try will produce a real wallet.
  • ✓Brute-force resistance — Argon2id key derivation (64 MB, 3 iterations) makes each password attempt computationally expensive.
  • ✓Strong Password — use the generator to derive a quantum-resistant password (>150 bits of entropy) from a memorable phrase in your native language. Store it as a password QR on a second plastic card.

Card Format

Card QR codes use the V4 envelope (basic honey encryption). The QR encodes a URL in the format:

https://w2qr.com/restore#ds=<base64url-encoded-data>

The ds parameter contains the honey-encrypted payload. Your password, processed through Argon2id, decrypts it into a valid BIP-39 mnemonic.