DRAM as source of randomness

Proposed is a true random number generator (TRNG) based on collision between DRAM accesses and refresh operations. The generator repeatedly executes a short code and reads a part of time counter register after each execution without an explicit post-processing. The simplicity allows the generation of true random numbers with a reasonable efficiency on commodity desktop computers without special devices and opens the possibility for simple TRNG on devices that use DRAM. Although very simple, the quality of the bit sequence is surprisingly good, as demonstrated by test results using NIST test suite.