Method and system for authenticating a user

A method for authenticating a service technician at a money transaction device, the method comprising:

• connecting a non-transitory removable storage medium of the service technician to a data processing system in the money transaction device, wherein
• a first storage area of the removable storage medium stores identification data for identifying the removable storage medium,
• the removable storage medium is a pluggable flash memory without a controller, and
• data of a digital certificate is stored in the first storage area or in a further storage area of the removable storage medium;
• reading the identification data and the data of the digital certificate from the storage area of the removable storage medium;
• transferring the identification data and the data of the digital certificate via a data transfer connection to the data processing system;
• in the data processing system, processing the identification data and the data of the digital certificate to authenticate the service technician;
• only in response to successful authentication of the service technician:
• transferring first data from the data processing system to the removable storage medium, and
• transferring the first data from the removable storage medium to a further data processing system not located in the money transaction device;
• and
• write and read accesses to the removable storage medium only being allowed when a valid certificate is stored on the removable storage medium, said certificate authenticating the user as having authorization to write to and read from the removable storage medium;
• wherein:
• the certificate specifies a public key of an asymmetric key pair of the user;
• the data processing system encrypts the first data with the public key to create encrypted first data that can be decrypted with a corresponding private key of the asymmetric key pair;
• and
• only in response to the successful authentication of the user, the data processing system transfers the encrypted first data to the removable storage medium.

A system for authenticating a user at a money transaction device, the system comprising:

• a non-transitory removable storage medium including identification data identifying the removable storage medium;
• a digital certificate stored on the removable storage medium, the digital certificate specifies a public key of an asymmetric key pair of the user, and identifies the user as having authorization to write to, and read from, the removable storage medium using the money transaction device;
• a data processing system of the money transaction device;
• a data transfer connection of the money transaction device configured to connect the removable storage medium to the data processing system of the money transaction device;
• wherein upon connection of the removable storage medium to the data transfer connection:
• the identification data and the digital certificate are transferred to the data processing system;
• the data processing system selectively authenticates the user based on the identification data and the digital certificate, and grants read and write access to the removable storage medium;
• subsequent to authentication of the user of the removable storage device, the data processing system transfers first data from the data processing system to the removable storage medium;
• the data processing system encrypts the first data with the public key specified by the certificate to create encrypted first data that can be decrypted with a corresponding private key of the asymmetric key pair;
• and
• the data processing system transfers the encrypted first data to the removable storage medium.