Live entropy

This is live entropy from the Zenerglass. The line represents the least significant byte of raw data samples of unamplified avalanche noise within a Zener diode. Not the characteristic log-normal distribution expected from a diode exhibiting avalanche effect? No, because we made the decision to sample in pairs as $ \text{sample} = x_i - x_{i + 1} + 128 $ and implemented as: = analogRead(portNo) - analogRead(portNo) + 128 and only use the lower 8 bits of the Arduino’s ADC ($N_{\epsilon} = 8$). It makes the graph a lot prettier and helps to achieve IID samples.

There are 200 data points on this graph, containing a true entropy of ~700 bits. You might therefore be able to identify about 5, 260, 135, 901, 548, 373, 507, 240, 989, 882, 880, 128, 665, 550, 339, 802, 823, 173, 859, 498, 280, 903, 068, 732, 154, 297, 080, 822, 113, 666, 536, 277, 588, 451, 226, 982, 968, 856, 178, 217, 713, 019, 432, 250, 183, 803, 863, 127, 814, 770, 651, 880, 849, 955, 223, 671, 128, 444, 598, 191, 663, 757, 884, 322, 717, 271, 293, 251, 735, 781, 376 unique versions of the above chart. That’s 4% of the total entropy available within a single request from the Zenerglass. This is based on a conservative entropy assessment of 3.5 bits /byte.

Note: We endeavour to maintain this entropy source on-line at all times, but that’s not always possible. Sometimes maintenance is required, and it goes off-line when the instrument needs polishing. Most Bank holidays are out too. There will be a big red error box and an “An Error Has Occurred…” message during the off times. Apologies.