The Calypso specifications are designed to improve and enhance any existing electronic ticketing application. They are used in fact, as part of a secure contactless system including: a central system, different front end terminals (reloading or re-charging appliances, validators, control devices, etc…), and portable devices (smart cards, mobile phones, USB keys). Calypso focuses essentially on the ticketing transaction between a terminal and a portable object.
Calypso has been designed to meet multi-modality, interoperability and multi-application requirements.
The ticketing transaction is organized into layers, as illustrated in this table:
The development of the Calypso ticketing application is based on international standards:
- Contactless communication:
ISO / IEC 14443 (Type B & A), defines the radio signal and protocol for an induction transmission at 13.56 MHz. For dual interface cards, ISO 7816 (1-3) describes the physical characteristics and the electronic signals and transmission protocols of Integrated Circuit Cards. It is also compatible with NFC (Type 4 Tag).
- The Card OS and file architecture:
ISO/IEC 7816-4 defines the card data organisation in a file structure’s basic card commands.
- Card data structure:
EN 1545, defines the coding of data elements used for public transport (such as: date, time, validation event, transport contract, etc.).
- Card and SAM security functions:
Calypso specifies the PO, SAM commands and files used during the ticketing transaction. These functions are optimized for ticketing (fast, secure) and include innovative patented technology such as the Secure Session and Ratification functions.
- Data Model:
describes the definition and the interpretation of the data in the files of the card, Calypso supplies a user-friendly generic data model for all ticketing systems. This data model is not fixed and can be tailored to the specific needs of each operator.
- Terminal Application Software:
ensures that the cards are managed in the same way by all terminals, and allows an easier enhancement of all kinds of terminals.
- Security Management and Architecture:
describes the management of the security for a ticketing system, and recommends good practices and all available choices for transport providers.