Storing Secrets on Continually Leaky Devices

We consider the question of how to store a value secretly on devices that continually leak information about their internal state to an external attacker. If the secret value is stored on a single device from which it is efficiently retrievable, and the attacker can leak even a single predicate of the internal state of that device, then she may learn some information about the secret value itself. Therefore, we consider a setting where the secret value is shared between multiple devices (or multiple components of a single device), each of which continually leaks arbitrary adaptively chosen predicates its individual state. Since leakage is continual, each device must also continually update its state so that an attacker cannot just leak it entirely one bit at a time. In our model, the devices update their state individually and asynchronously, without any communication between them. The update process is necessarily randomized, and its randomness can leak as well. As our main result, w...

• Type: Journal
• Year: 2011
• Where: IACR
• Authors: Yevgeniy Dodis, Allison B. Lewko, Brent Waters, Daniel Wichs
• Keywords: Encryption Scheme, IACR 2011, Independent Interest, Public Key Encryption