Summary: NIST is implementing a prototype source of public randomness. The prototype (at uses two independent commercially available sources of randomness, each with an independent hardware entropy source and SP 800-90-approved components. The Beacon is designed to provide unpredictability, autonomy, and consistency. Unpredictability means that users cannot algorithmically predict bits before they are made available by the source. Autonomy means that the source is resistant to attempts by outside parties to alter the distribution of the random bits. Consistency means that a set of users can access the source in such a way that they are confident that they all receive the same random string.

Description: The Beacon will broadcast full-entropy bit-strings in blocks of 512 bits every 60 seconds. Each such value is time-stamped and signed, and includes the hash of the previous value to chain the sequence of values together. This prevents all, even the source, from retroactively changing an output packet without being detected. The beacon keeps all output packets and makes them available online. Uses: Tables of random numbers have probably been used for multiple purposes at least since the Industrial Revolution. The first published table appears to be by the English statistician L.H.C. Tippett. In the digital age, algorithmic random number generators have largely replaced these tables. The NIST Randomness Beacon expands the use of randomness to multiple scenarios in which the latter methods cannot be used. The extra functionalities stem mainly from three features. First, the Beacon-generated numbers cannot be predicted before they are published. Second, the public, time-bound, and authenticated nature of the Beacon allows a user application to prove to anybody that it used truly random numbers not known before a certain point in time. Third, this proof can be presented offline and at any point in the future. For example, the proof could be mailed to a trusted third party, encrypted and signed by an application, only to be opened if needed and authorized. NIST encourages the community at large to research and publish novel ways in which this tool can be used. A few examples of applications are described below:

FEDERATION: several parties have private inputs; they wish to compute a function of these inputs without compromising the privacy of the inputs. "authenticated broadcast" of Beacon used as secure multiparty computational solution
 - “challenge-response protocol”. The need for both parties to be assured that the other does not control the challenge is critical for security.  
UNPREDICABLE SAMPLING:  UN-RIGGED REWARD SYSTEMprotecting against industrial sabotage, assuring quality control, preventing clandestine protectionist measures, ensuring accuracy of environmental testing, reward systems, prize awards, donations to charity etc.