Abstract: Methods and devices for of conducting a payment transaction between a mobile terminal and a payment terminal in communication with a payment backend system involve: (a) sending a unique mobile terminal identifier from the mobile terminal to the payment backend system; (b) returning a cryptogram from the payment backend system to the mobile terminal, wherein the cryptogram comprises a unique transaction identifier in encrypted form; (c) transforming the cryptogram into a proximity payment token such that the proximity payment token contains the unique transaction identifier in encrypted form and transmitting the proximity payment token to the payment terminal via a proximity communication channel; (d) forwarding a transaction record including the unique transaction identifier in encrypted form and the amount of the payment transaction from the payment terminal to the payment backend system; and (e) decrypting the unique transaction data identifier in encrypted form and processing the payment transaction.

Abstract: Methods and devices for of conducting a payment transaction between a mobile terminal and a payment terminal in communication with a payment backend system involve: (a) sending a unique mobile terminal identifier from the mobile terminal to the payment backend system; (b) returning a cryptogram from the payment backend system to the mobile terminal, wherein the cryptogram comprises a unique transaction identifier in encrypted form; (c) transforming the cryptogram into a proximity payment token such that the proximity payment token contains the unique transaction identifier in encrypted form and transmitting the proximity payment token to the payment terminal via a proximity communication channel; (d) forwarding a transaction record including the unique transaction identifier in encrypted form and the amount of the payment transaction from the payment terminal to the payment backend system; and (e) decrypting the unique transaction data identifier in encrypted form and processing the payment transaction.

Abstract: Secure data processing is carried out on a computer system with a higher-level or coordinated secure operating system that is not visible for a user. The secure operating system as a computer program application provides a virtual machine with virtual computer hardware on which a user operating system visible and usable for the user can be executed and which has at least one virtual mass memory with a file system of the user operating system or the secure operating system is encapsulated in a first virtual machine and the user operating system visible and usable for the user and equipped with at least one virtual mass memory with a file system is executed in a second virtual machine. The secure operating system cannot by manipulated by the user or a computer program application, in particular a harmful file.

Abstract: A security token is scanned by a pure reader that is connected to a computer. This immediately loads from the token into the computer a virtual machine having a virtual operating system. Then an identification/authentication code is entered via a peripheral of the computer, whereupon data can be exchanged between the security token and the virtual operating system, and thence exchanged between the virtual operating system and a remote location.