A communication network can include a random number beacon broadcasting a random number stream to multiple computing devices. At least two of those computing devices can generate private keys for secured communication based a subset of random numbers from the random number stream. Other devices do not have access to these private keys even though they have access to the subset of random numbers by virtue of receiving the broadcasted random number stream. The subset of random numbers can be extracted based on a predetermined time known only to the two or more devices, and/or the subset of random numbers can be extracted following detection of a predetermined number sequence in the random number stream known only to the two or more devices. Following a similar concept, a computing device can generate private cryptographic keys from a public random number stream.