How would copyright law affect a seedable random text generator?
<p>Lets say I create a program that generates random text based on a seed value.</p>

<p>I then create a secondary program, which uses incremental seeds with the initial program to generate several trillion strings of text. It compares each string against a library of copyrighted works to see if there are matches, and writes down the seed alongside the name of the work if it does.</p>

<p>The end result is a list of seeds that can be used with the original program to generate a specific copyrighted work.</p>

<p>What would then be the legal status of these seeds? Would sharing them be considered copyright infringement?</p>

<p>I believe this is an open issue in copyright law at this time.</p>

<p>First off, I'd like to point out that you might be underestimating the seed.  You should expect, on average, a seed which can reproduce a 10kB novel will be roughly 10kB in length.  It's basically a fancy encoding of the existing work.  You're unlikely to find a 10 digit seed which, when run through your algorithm reproduces a work of Shakespeare.  Also, as the original work was used in the production of this seed, it would likely be considered to be a derivative work.</p>

<p>However, because this <em>is</em> a number, the famous controversy over the <a href="https://en.wikipedia.org/wiki/AACS_encryption_key_controversy" rel="nofollow noreferrer">AACS encryption key</a> is relevant.  Hackers identified a key critical to decrypting HD-DVDs and posted it online.  The MPAA and AACS LA began issuing cease and desist letters, arguing the number was copyrighted.  To my knowledge, no official answer as to whether or not one can copyright a number in this way was ever reached.  The issue was handled out of court, with the final result that the AACS went after anyone trying to use the number to break the encryption, but permitting discussion of the number without threat of legal action.</p>

<p>So, you have an <a href="https://en.wikipedia.org/wiki/Infinite_monkey_theorem" rel="nofollow noreferrer">infinite monkey</a> machine. More precisely, what you have described is a decompression program (zip/unzip) into which you feed a randomly generated seed.</p>

<p>Since you did not copy the material, you will not have violated copyright law.</p>

<p>However, if the copyright owner were to bring a case they would probably win. That's because cases are decided on the balance of probabilities and the no matter what evidence you provide, their expert evidence based on the infinite monkey theorem, will show it is way more likely that, for a work of any reasonable complexity (like this answer), the number you have was generated by pushing the original work through your algorithm backwards rather than generating it randomly and it happening to correspond with an actual intelligible piece of writing.</p>

<p>You will, of course have copyright in your algorithm.</p>

copyright