Secure and Robust Error Correction for Physical Unclonable Functions One area of research that has not received much attention is the amount of information leakage due to error correction in practical PUF-based key generation systems. In this paper, we propose a new Syndrome Coding scheme, called Index-Based Syndrome (IBS) Coding. It differs from conventional syndrome coding methods in that it leaks less information than conventional methods or other variants that use bitwise XOR masking. Under the assumption that PUF outputs are i.i.d., IBS can be shown to be information-theoretically secure. The assumptions required to prove this result have been affirmed using NIST Randomness Tests. Further, IBS coding has coding gains associated with the soft decision encoding and soft decision decoding that is native to IBS, resulting in robust error correction. A Xilinx Virtex-5 implementation had no error correction failures over millions of trials when provisioned at 25oC and 1.0V, regenerated at 120oC and .90V and at -55oC and 1.1V.