The invention relates to a smart card (100) with a storage medium. The smart card is configured such that applications (132) which are installed on the storage medium and which do not belong to the same security domain (SD1-SD5, SD8) are isolated from one another. At least one persistence application (202) and a main application (204) are installed on the storage medium. The persistence application (202) is assigned to a first security domain (SD8) and is protected from being accessed by means of any application (134) external to the smart card. The persistence application includes a program logic (210) for storing data (D8) on the storage medium (108) and for reading the stored data. The main application (204) is likewise assigned to the first security domain (SD8) and includes an interface (AI) for an application (134) external to the smart card and an additional interface (208) for exchanging the data (D8) with the persistence application. The main application includes a program logic (206) for processing the data (D8), said program logic being configured such that already processed data (D8) is transmitted to the persistence application via the additional interface (208) in order to be stored on the storage medium (108), and data to be processed is received by the persistence application via the additional interface (208).