Overview

The NIST Randomness Beacon is a public randomness service run by the US National Institute of Standards and Technology that publishes a fresh, cryptographically signed random pulse roughly once a minute, each pulse linked to the previous in a tamper-evident chain. In Truestamp it is one of the three entropy sources: each new pulse is captured by HTTP polling and stored as an entropy observation that keeps only the essential fields (the random output value, the chain and pulse indices, the pulse timestamp, and the API version). External verification re-fetches the pulse from NIST’s public API using the stored chain and pulse indices and compares the chain index, pulse index, output value, and timestamp against what NIST published; see verification levels for where that check fits. What each source contributes to the timing guarantee is covered in entropy sources.