RCRand
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dasmithii
race condition based random number generaton
Note (!)
This project is by no means cryptographically secure, and shouldn't be used for non-recreational purposes. It's a mere hack, really - a playful experiment on my part.
If you take a more serious approach (or not), please do get in touch! I'd love to converse/discuss/collaborate on similar ideas. Pull requests welcome.
Introduction
After struggling with a race condition issue for an hour or two, I decided to make use of this wonderful unpredictability that is shared resource mutation.
Here's the (summarized) algorithm. It's analogous to a busload of monkeys frenzying over a lego structure, where monkeys are worker threads and lego structure represents memory contents. As they chaotically rearrange blocks, interfering with each other at times, snapshots are taken periodically and translated into integral form. For all practical purposes, these are random numbers.
(1) Setup
- Obtain a byte buffer from unix rand(). This serves as a starting point for the output sequence.
- Spawn a thread pool.
(2) Generation
- Have each worker thread mutate the byte buffer concurrently, without mutex locks or et cetera.
- For each byte generation request, XOR all bytes in the buffer and return the result. During this time, worker threads continue.
- Ensure that at least one operation has been performed on the buffer between each byte output.
(3) Tear-down
- Cancel all worker threads.
Installation
git clone [email protected]:dasmithii/RCRand.git
cd RCRand
cmake .
make install
Usage
The bytes option specifies an output count.
$ rcrand --bytes 5
ȅc!PV
By switching on format, you can print a more human-readable output.
$ rcrand -format --bytes 5
81
90
151
215
186
If bytes aren't specified, output will continue indefinitely.
rcrand -format
142
206
144
242
65
219
81
220
13
204
(... continued)
Visualization
dasmithii