From Stateful Hardware to Resettable Hardware Using Symmetric Assumptions

Universally composable multi-party computation is impossible without setup assumptions. Motivated by the ubiquitous use of secure hardware in many real world security applications, Katz (EUROCRYPT 2007) proposed a model of tamper-proof hardware as a UC-setup assumption. An important aspect of this model is whether the hardware token is allowed to hold a state or not. Real world examples of tamper-proof hardware that can hold a state are expensive hardware security modules commonly used in mainframes. Stateless, or resettable hardware tokens model cheaper devices such as smartcards, where an adversarial user can cut off the power supply, thus resetting the card’s internal state. A natural question is how the stateful and the resettable hardware model compare in their cryptographic power, given that either the receiver or the sender of the token (and thus the token itself) might be malicious. In this work we show that any UC-functionality that can be implemented by a protocol using a...

• Type: Journal
• Year: 2016
• Where: IACR
• Authors: Nico Döttling, Daniel Kraschewski, Jörn Müller-Quade, Tobias Nilges
• Keywords: Biometrics, IACR 2016