speaker: Ariel Gabizon (SFU) title: A Recycling Paradigm for Extracting many Random Bits abstract: Randomness Extractors are algorithms which extract random bits from a "weak" random source. A simple example of a weak random source is a biased coin. An extractor for this source (which was given by von Neumann) would be an algorithm that uses the biased coin tosses to produce unbiased uniformly distributed bits. Another example of a weak random source is an (n,k)-bit-fixing source: A distribution on n bits that are all independent, where some unknown subset of k bits is uniformly distributed, and the other n-k bits are constants. It is easy to see that taking the parity of all bits gives a random bit. Based on joint work with Ran Raz and Ronen Shaltiel.