Case study A-Trust

Mobile TANs for secure digital signatures

A-Trust is an accredited provider of qualified certificates for the creation of secure digital signatures in Austria. In addition to the “Bürgerkarte” (citizen card), 2010 also saw the introduction of the mobile signature. For this purpose, atms took over the mobile TAN sending service from an Austrian mobile operator and optimized it for A-Trust.

“The SMS messaging solution from atms has not only allowed us to save costs, it has also enabled us to reduce the error rate thanks to the highly reliable technical implementation of the solution.”

5 Sterne für atms

Michael Butz, Managing Director A-Trust


In addition to the citizen card for electronic signatures, 2010 also saw the introduction of the mobile signature. The mobile signature is accorded the same status as a person’s handwritten signature and functions as a form of electronic ID which can be used to sign official or commercial documents quickly and easily in a legally binding manner. More than 860,000 people in Austria already use the mobile signature.

The mobile signature is created by A-Trust via a mobile TAN and requires the technical SMS messaging operator to have high standards of security, availability and service. Quick delivery of the mTAN SMS, including delivery confirmation, as well as an adjustable SMS validity period, must be guaranteed.

atms Solution

atms took over the mobile TAN sending service for A-Trust from an Austrian mobile operator. The mobile signature is handled via atms’s own redundant data centre and its connections to all Austrian mobile operators.

Should a connection with a mobile operator experience a temporary fault, atms will, within a few seconds, send the mobile signature via another mobile operator by means of a “back-up routing” mechanism developed in-house. The immediate provision of a delivery message means that A-Trust can be sure that the SMS has been sent to the relevant mobile phone.

Thanks to the reliable SMS messaging solution from atms, the error rate – i.e. the number of undelivered SMS messages – has been reduced significantly. The internal servicing requirement has therefore also decreased. Furthermore, the switch to the mTAN solution from atms means that “A-Trust” can now be used as the sender ID for SMS messages. This helps to boost acceptance of mobile signatures and simultaneously enhances the feeling of security among users.

Are you interested in a similar solution? Get more infos about the m-TAN solution from atms here:

Created on: 07/11/2011