Method for Securing a Transaction

1 - 17 . (canceled)

18 . A method for securing a payment transaction, between a communication end device and a server instance, the communication end device comprising a processor with an insecure runtime environment and a secure runtime environment, the method including the steps of:

setting up a first communication channel between the communication end device and the server instance;

sending transaction-relevant data from the communication end device to the server instance via the first communication channel, wherein:

before the sending step a second communication channel is set up between the browser application in the insecure runtime environment and a transaction application in the secure runtime environment;

before the sending step at least a part of the transaction-relevant data is sent to the transaction application via the second communication channel;

before the sending step the transaction application generates from the received part of the transaction-relevant data a confirmation information item for securing the transaction; and

wherein the confirmation information item is employed for authorizing the transaction in the server instance.

19 . The method according to claim 18 , wherein the confirmation information item also contains data of the browser application about the first communication channel and/or further transaction-specific data.

20 . The method according to claim 18 , wherein the transaction-relevant data are entered by the user into a browser application in the insecure runtime environment and before the sending step at least a part of the entered transaction-relevant data is sent to the transaction application via the second communication channel.

21 . The method according to claim 18 , wherein at least a part of the transaction-relevant data is made available by the server instance via the first communication channel and before the sending step at least a part of the inputted transaction-relevant data is sent to the transaction application via the second communication channel.

22 . The method according to claim 18 , wherein at least a part of the transaction-relevant data is made available and/or generated by the transaction application.

23 . The method according to claim 18 , wherein the transaction application:

checks the transaction-relevant data in the secure runtime environment;

if the check yields an inconsistency of parts of the transaction-relevant data:

displays a warning message to the user via an output element of the communication end device; and/or

prevents the sending of the transaction-relevant data to the server instance.

24 . The method according to claim 18 , wherein the confirmation information item contains an information item uniquely identifying the secure runtime environment.

25 . The method according to claim 18 , wherein:

the transaction application in the secure runtime environment sets up a third communication channel to the bank instance; and

the confirmation information item is sent to the bank instance while employing parts of the transaction-relevant data, before the transaction-relevant data are sent to the server instance.

26 . The method according to claim 25 , wherein

the server instance sends the transaction-relevant data received from the communication end device to the bank instance at least partly;

the bank instance compares the confirmation information item with the transaction-relevant data sent by the server instance; and

the bank instance authorizes or prevents the transaction in dependence on the comparison.

27 . The method according to claim 18 , wherein the transaction application:

codes the confirmation information item into the transaction-relevant data;

makes the transaction-relevant data with the coded-in confirmation information item available to the browser application; and

the transaction-relevant data with the coded-in confirmation information item are sent to the server instance as the transaction-relevant data.

28 . The method according to claim 27 , wherein the confirmation information item is coded into an owner-specific part of a credit card number, thereby generating a changed credit card number.

29 . The method according to claim 28 , wherein the changed credit card number is sent to the server instance as part of the transaction-relevant data, instead of the credit card number.

30 . The method according to claim 18 , wherein the transaction application in the secure runtime environment encrypts the transaction-relevant data cryptographically by means of a key associated with this secure runtime environment.

31 . The method according to claim 18 , wherein an affiliation of at least parts of the transaction-relevant data, and the secure runtime environment was communicated to a bank instance before the first-time performance of the method.

32 . A computer program product which can be loaded directly into the internal memory of a processor within a digital communication end device and comprises software code portions with which the steps according to claim 18 are performed when the computer program product runs on the processor.

33 . A communication end device having means for carrying out the method according to claim 18 and having:

a processor unit with an insecure runtime environment and a secure runtime environment;

an input unit for inputting transaction-relevant data;

an output unit for outputting transaction-relevant data;

a first interface for setting up a first communication channel and sending) transaction-relevant data;

wherein a browser application in the insecure runtime environment has an extension module, and this extension module has a second interface for setting up a second communication channel to a transaction application in the secure runtime environment, and the transaction application can access at least parts of the inputted transaction-relevant data via the second communication channel in order to generate a confirmation information item for securing the transaction.

34 . A system having means for carrying out the method according to claim 18 , having:

a communication end device;

a server instance; and

a bank instance;

wherein the communication end device has a secure runtime environment and this secure runtime environment is identifiable uniquely by means of a cryptographic key on the system.