Figure 3: Running time of RRB compared with other extractors.
Running time is measured on input samples of size 1 GB–20 GB for von Neumann extractor, local hash extractor (with block-size 1024 bits), and for RRB (with k = n/4, n/8, n/16 and ε = 10−10, 10−20, 10−30). Trevisan’s extractor is only measured for ε = 0.001 on samples of size up to 5 MB = 4 × 107 bits, since the available implementations of finite fields cannot handle larger samples or smaller ε. The running time of Trevisan’s extractor on larger input size (in particular, 103,407 years for 20 GB input) is estimated by polynomial fitting assuming all data in the main memory, which is an unrealistic advantage. The exact form of the fittest polynomial is determined through cross-validation and standard analysis of polynomial norms.
