Tuesday, June 09, 2009

your brain on CSPRNG

Not too long ago I used a cryptographically secure pseudo-random number generator API for assigning unique identifiers to users for requesting an unauthenticated but personalized semi-sensitive resource over the Internet. They already have the typical unique organizational IDs assigned to them in the internal databases, but these IDs are far from secret. As much as possible, the resource identifier/URL for a particular user had to be unpredictable and incalculable (and also had to represent sufficient bits such that a brute force attack is impractical, which is no big deal from a performance standpoint because these identifiers are only generated on request). Also, we've committed to the unauthenticated resource itself not containing any truly sensitive details - the user simply must log in to the actual web site to view those.

Anyhow, as my mind was drifting aimlessly before I got my coffee today, I wondered if the CSPRNG could be an analogy for the brain's creativity. Unlike a plain pseudo-random number generator that's seeded by a single value, the CSPRNG has many inputs of "entropy" or uncorrelated bits. The bits can come from any number of sources in the computer system itself, including the hardware, which is one reason why the CSPRNG is relatively slow at processing random numbers.

But like a CSPRNG algorithm the brain is connected to myriad "inputs" all the time, streaming from within and without the body. Meanwhile, the brain is renowned for its incredible feats of creativity. It's common for people to remark "that was a random thought" and wonder "where that came from". Given all these entropic bits and the stunning network effects of the cortex (an implementation of "feedback units" that outshines any CSPRNG), should we be surprised that the brain achieves a pseudorandom state? I hesitate to call it true randdomness in the same way as someone who believes the brain relies on quantum-mechanical effects; people who try to recite a "random sequence" tend to epically fail.

I'm not sure that this makes any real sense. I'm not suggesting that a CSPRNG is a suitable computational model for human thought. It's merely interesting to ponder. It's another reminder that just as software isn't a ghost-like nebulous presence that "inhabits" a computer - a microprocessor engineer would tell you that each software instruction is as real as the current that a pacemaker expels to regulate a heartbeat - our thoughts and minds are inseparable from the form or "hardware" of the brain, and the brain is inseparable from the nervous system, and the nervous system is inseparable from the rest of the body.

1 comment:

  1. Anonymous9:26 AM

    Maybe you are not so far off the mark. A single neuron in the brain gets signals from many sources and sends out only one signal. Maybe the CSPRNG could be viewed in the same light. Now you only need to figure out how to make approximately 100 billion of them work together and that might be a sentient artificial mind.

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