Pseudorandom numbers may be generated from input seeds using expander graphs. Expander graphs are a collection of vertices that are interconnected via edges. Generally, a walk around an expander graph is determined responsive to an input seed, and a pseudorandom number is produced based on vertex names. Specifically, a next edge, which is one of multiple edges emanating from a current vertex, is selected responsive to an extracted seed chunk. The next edge is traversed to reach a next vertex. The name of the next vertex is ascertained and used as a portion of the pseudorandom number being produced by the walk around the expander graph.