Calypso

Direct Answer

Calypso is an open international contactless electronic ticketing standard managed by the Calypso Networks Association, operating under ISO/IEC 14443 Type B (and Type A). Developed by European transit operators to prevent proprietary lock-in with NXP MIFARE, it powers major transit networks including the Paris Navigo, Lisbon Viva, and Belgium MoBIB.

Source: Calypso Networks Association / ISO/IEC 14443-B / EN 1545 · Last reviewed Aug 28, 2026

Specs

Frequency Bands	13.56 MHz
Framing Standard	ISO/IEC 14443 Type B (and Type A in Calypso Prime)
Standardization Body	Calypso Networks Association (CNA) / EN 1545 / ISO 24014
Cryptographic Engine	Triple DES / AES-128 / Elliptic Curve PKI (Calypso Prime)
Operating Architecture	Multi-application secure microprocessor (Java Card / Native OS)
Primary Transit Deployments	Paris (Navigo), Brussels/Belgium (MoBIB), Lisbon (Viva), Venice, Tel Aviv (Rav-Kav)

Open Standard Anti-Lock-In Genesis

In the late 1990s, public transit authorities across France, Italy, Belgium, and Portugal formed the Calypso consortium under an EU funding initiative. Unlike proprietary single-vendor architectures (such as NXP's MIFARE Classic or Sony's FeliCa), Calypso licenses its secure session specifications openly, enabling operators to procure compatible silicon and smart cards from competing semiconductor manufacturers (STMicroelectronics, Infineon, NXP, Watchdata).

Secure Session and Transaction Atomicity

Calypso executes transactions using a certified cryptographic 'Secure Session'. When a card enters the turnstile RF field, a cryptographic session key is computed via 3DES or AES-128. If an interrupted tap occurs mid-transaction, Calypso's atomic rollback mechanism guarantees the electronic purse balance is never corrupted or improperly debited.