In order to carry out a Contactless Ticketing transaction between a card and a reader, it is necessary to implement the seven layers of the transaction framework:


Security Management and Architecture Calypso Security Architecture
Terminal Applicative Software Calypso API
Data Model Calypso Data Model
Card and SAM Security Mechanisms Calypso card application
Card Data structure CEN EN 1545
Card OS and Files structure & Commands ISO/IEC 7816-4
Contactless Communication Interface and Contact Communication Interface ISO/IEC 14443
ISO/IEC 7816-3


To achieve interoperability among different suppliers, it is necessary for all products to implement these layers in the same way.
The Calypso interoperability therefore requires:

  • The strict application of standards' rights: ISO 14443, ISO 7816-4, EN 1545
  • The use of the CALYPSO secured transaction (card commands)
  • The use of the same data instantiation (strictly the same adaptation of the generic data model for all system partners)
  • The same data model
  • The bringing into play of a common security architecture

Concerning an interoperable application, in the case of several operators, the data model and its position in the final central system, should be determined by a common architecture agreed by all various actors.
In short, to ensure interoperability, it is necessary for all terminals sharing the use of the same cards to agree on these precise characteristics (definition and use, layout, organisation in the card file system): this is defined in fact, by the agreed card Data Model.

Calypso therefore offers a time proven and operational interoperability technical standard.