The Random Page

2023-05-27 | [radiclock]
next: Atomic Clock

lol so random

As part of my atomic clock project I also produce random numbers (why not). Radioactive decay is a well known method to generate true randomness because no one can predict which or when an atom will decay. This technique was used for years in the famous HotBits project which is sadly shut down as of 2023. I have a radioactive sample of my own, but, there's a ways to go from a Geiger counter to a number. How does this work?

  1. Radiation from my sample of pitchblende gets detected by one of my radiation sensors. These are the "clicks" you hear from a geiger counter.
  2. There is a timer running all the time. When a pulse from the sensor comes in, take the timestamp of it. If you want to slow down the rate, you can take the time every nth pulse instead. Whatever the setup, do this until you have 4 timestamps.
  3. Do a quick check to make sure the timestamps are in order (in case the timer overflowed)
  4. Take the 4 timestamps, and generate 2 intervals:
  5. If interval0 > interval1, that's a 0. If interval1 > interval0, that's a 1. If the 2 are equal, throw out the sample and try again.

I actually have 2 sensors; one is a classic Geiger–Müller tube, and the other is PIN-diode based. I collect random numbers from each. I didn't know quite what to do with the numbers I collected, so I figured I would publish them live.

The 2 detectors are set up to generate random bits at around the same rate - about 32 bytes every 55 seconds. The full 1024 byte frames shown and linked below will update about once every half hour. Therefore, please do not spam us with requests. Also, be sure to check the ISO 8601 timestamp at the start of each file, and make sure it's somewhat close to the current time. If it isn't, the project is either broken, or you are getting a cached copy (check your browser).

Also, a most important note: the data listed here is published globally, not individually, like HotBits or random.org. In other words, it is not unique to you. I highly recommend you do not use this for security purposes as it it possible another party may have a copy of the data.

From the GM tube (hex format):

2025-09-06T17:18:08.799764+00:00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From the PIN diode (hex format):

2025-09-15T22:52:18.481705+00:00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Ok, so you want decimal digits instead? I've come up with this technique:

  1. Look at each byte. It's a number from 0-255. Throw out any samples greater than 199, and we now have a range from 0-199
  2. Convert those samples to a 3 digit string, then throw away the first digit. Now, we have random numbers from 0-99
  3. Concat those strings into a really long string. Now, we have a sequence of random digits. But, the string can vary in length.
  4. To deliver something with consistent length, I can just trim the string. But by how much? Since the probability of a skipped byte is 56/256, we would expect about 800 of 1024 bytes to be usable samples. There's a 50% chance there will be more than 800 good bytes. But, there's about a 99.99% chance there will more than 750 bytes. I still double check to make sure, but that's what I publish. Of course, that gives 1500 digits.

To determine where to make the cut, look up the binomial distribution probability. It's already built into spreadsheets as BINOM.DIST, which is what I used.

From the GM tube (digits):

2025-09-06T17:18:08.799764+00:00
98927433848248141101116537321085423190765260004678
11958307248995560821377115972371459682555458172607
38027220599454068056580585424289120195135808018911
81730326587260459146582170501178211539443530738873
14302158744574723126720989003647197879251062145393
95588392559171837068631580254328808020066587685766
69662773830196184153615022635702433077214838306566
23567471140858515082906309348557575678781969771386
29855400856080351233081625132866049622227385713306
31127091898628316188225410523421273390176131544427
99816633896226429074801093922236986757027387711579
70677640712258841717191063849895241625684383472606
20149439380372494396662960714003908659647930405116
02651805123832615900434097988283723560321632624283
34446560096922919662554056309033862127003563651054
04649951297636990696040006870385574603556592121620
99258124743473144505665600485083775011116518575504
29503334089296436203804383703448871964197169390338
82222311649271398236367949163006969009372079953751
07098286940416690731750748235166049907070875975855
90538707805013527141402204096237977709806659315029
20763830744177064647201419763109266501458979086625
85077086741145362187415208158427336595661969384775
54382333534286312679468035160229214715992269549801
33927963413978460874569988482814122929506131110327
19148428956747029719865805343612973616038745886410
92521169075346681306367382439294393181281090265267
55493725775342045165038426686900388140472152416300
47967055447875015902009620726602562852161582948148
30950992559580630418151671285466165141333105283072

From the PIN diode (digits):

2025-09-15T22:52:18.481705+00:00
56219268602207448861074463394104181706359146372662
32808411573451964814405675984591801113817326242014
87638459505301141864703964294558355881457610124468
37742135513523620538192991673038687418944875276090
37288653029407807131967400276410162082406296496783
96759721920478350974883730912571292329377374059212
72384422069233326392137617251242393863916918567123
35290509539687861840985275675691081980960453018861
39052822706983988653417145177713043137144941942331
03608674123775739382120631133879709602928042935932
09141664576479081727944710579494356947711092361943
51517500710994726794488297530732554264132927491851
63797389524084971806547270587853140260848591216230
52574156029420197270110235060822923275482373934620
68021651192799469715910756925099443677242510421452
18542691163179893540470496049224422075997202954988
72478933067667498176904051254380685278342003348735
60476418367992654425491509341595369678170629065384
22823194327569289058146478704401769883074886297495
29100833726121146448033055948160855232104560008341
62753793613191373961903939673489265273968656196567
74644596446280825942492646001445504738196096819499
43148987702761198102486691314787189869233474385574
05449204765100290875816185346830009101845484755460
61581348694039088943761951528326855600630652340831
43047106872919371790563297324818662592006967993034
14589418838004158959316713921316757703754699588048
11982114779046727681535828778712287291741300309215
92293863795898092142515953287187227406278760052812
38600457817612047757756317159140308011867646363736

Or, perhaps you want just the raw bytes themselves. Just make sure to trim away the first 33 bytes which are the timestamp header:

Here is the python program I use to generate the reports above.

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