Multiple observations for secret-key binding with SRAM PUFs

We present a new Multiple-Observations (MO) helper data scheme for secret-key binding to an SRAM-PUF. This MO scheme binds a single key to multiple enrollment observations of the SRAM-PUF. Performance is improved in comparison to classic schemes which generate helper data based on a single enrollment observation. The performance increase can be explained by the fact that the reliabilities of the different SRAM cells are modeled (implicitly) in the helper data. We prove that the scheme achieves secret-key capacity for any number of enrollment observations, and, therefore, it is optimal. We evaluate performance of the scheme using Monte Carlo simulations, where an off-the-shelf LDPC code is used to implement the linear error-correcting code. Another scheme that models the reliabilities of the SRAM cells is the so-called Soft-Decision (SD) helper data scheme. The SD scheme considers the one-probabilities of the SRAM cells as an input, which in practice are not observable. We present a new strategy for the SD scheme that considers the binary SRAM-PUF observations as an input instead and show that the new strategy is optimal and achieves the same reconstruction performance as the MO scheme. Finally, we present a variation on the MO helper data scheme that updates the helper data sequentially after each successful reconstruction of the key. As a result, the error-correcting performance of the scheme is improved over time

On multiple access channels with feedback

For the binary erasure multiple access channel, van der Meulen showed in his survey paper that the symmetrical rate pair (0.79113, 0.79113) is achievable in the case of feedback. Here we prove that this rate point is on the boundary of the feedback capacity region/Subsequently we apply this result to demonstrate the fact that the feedback capacity region of the product of two multiple access channels can be strictly larger than the (Minkowski) sum of the feedback capacity regions for the separate channels

Totally asynchronous slepian-wolf data compression

It is proved that the Slepian-Wolf data compression theorem (1973) still holds when both encoders are operating totally asynchronously. In addition it is shown that in this case the Wyner-Ahlswede-Körner source coding theorem (1975) holds

The discrete memoryless multiple access channel with partially cooperating encoders

We introduce the communication situation in which the encoders of a multiple access channel are partially cooperating. These encoders are connected by communication links with finite capacities, which permit both encoders to communicate with each other. First we give a general definition of such a communication process (conference). Then, by proving a converse and giving an achievability proof, we establish the capacity region of the multiple access channel with partially cooperating encoders. It turns out that the optimal conference is very simple