Von Ralf Keuper
Gibt es eine Möglichkeit, Dienste im Internet in Anspruch zu nehmen, ohne dass dabei Daten ausgetauscht werden, die für die eigentliche Transaktion nicht nötig sind?
A homomorphic encryption scheme is a crypto system that allows computations to be performed on data without decrypting it. A homomorphically encrypted search engine, for instance, could take in encrypted search terms and compare them with an encrypted index of the web. Or a homomorphically encrypted financial database stored in the cloud would allow users to ask how much money an employee earned in the second quarter of 2013. But it would accept an encrypted employee name and output an encrypted answer, avoiding the privacy problems that usually plague online services that deal with such sensitive data.
Die Prinzipien der homomorphen Verschlüsselung wendet ein Protokoll namens ORide, das von der EPFL und der UNIL entwickelt wurde, um den Datenaustausch zwischen einem Fahrgast, der Uber nutzt, und dem Fahrdienst so zu regeln, dass nur die Daten offengelegt werden, die für die Fahrt benötigt werden.
The only data seen by the ride-hailing company is the distance travelled and the cost of the ride, since this information is what the company will use to take its cut of the fee and what passengers will use as a record of their travel expense. What’s more, ORide doesn’t affect the app’s convenience – passengers can still pay with their credit cards and evaluate their drivers. “Our protocol was designed not to provide complete anonymity, but to make it very hard to track the passengers’ and the drivers’ movements,” says Hubaux. The researchers also realized that their system needs to allow passengers to hunt down a lost item or provide evidence in case of a dispute with a driver. In the event of such a dispute, the data can be re-identified, but only with the agreement of the party making the complaint.