Not an expert at all but I’m genuinely curious how long it would take to check all possibilities for each I or 1? Is that the full length of the hash or whatever? So in this example image we have 2^8 =256 different possibilities to check? Seems like that would be easy enough for a computer.

Edit: actually read the article. It’s much more complicated than this. This isn’t really the only issue and the base64 in the example was 76 pages long.