Two major patents are included in the Calypso licenses.

Setting-up a Calypso ticketing system requires using two patents:

  • Session patent, which guarantees the data integrity within the card in all possible situations, even if the card is removed from the transaction area during the exchanges of information with the reader.
  • Ratification, which allows correctly ending a transaction even if a problem occurs during the final acknowledge of data transmission.

The fees resulting from the use of these two Calypso patents are known under the wording “Calypso license”.