Actually I was trying to express that the birthday paradox does not apply when you to find a plaintext that evaluates to a known hash, as you'd need to do for password cracking or forging a signed email for example[1]. The birthday paradox only gives you the probability that of a random set of hashes, two are the same. It's "if I generate n random pieces of plaintext, how big is the chance that two of them generate the same hash." Actually it gives you the probability of picking the same element twice from a finite set of elements when you pick n times.
[1] When generating emails more restrictions apply: The colliding plaintexts have to be at least somewhat coherent and probably should express something the attacker wants to express.
Yes, and that's exactly the point that is addressed in the box I quoted.
You're exactly right, and I believe it's covered. I didn't go into detail about the problems involved in generating a plain text that hashes to a specific hash,such as you mention. I did simply mention that the problem I'm talking about is not that one.
So I don't understand the point dsego was making, because I think my reference is relevant.
At this point I'm no longer sure it really matter.
[1] When generating emails more restrictions apply: The colliding plaintexts have to be at least somewhat coherent and probably should express something the attacker wants to express.
Edit: Forgot a negation in a crucial place. Darn.