Well, that’s a collision attack; I don’t think we’ve seen a way to create an arbitrary pair of souls, and if we had it’d probably be obvious on their admission. Though I’d read the story of someone breaking preimage resistance on the Hogwarts wards and using that to, say, get a toad credentialed as the Muggle Studies professor. It’d probably do a better job...
And given that MD5 is broken that could lead to interesting consequences… :-D
Well, that’s a collision attack; I don’t think we’ve seen a way to create an arbitrary pair of souls, and if we had it’d probably be obvious on their admission. Though I’d read the story of someone breaking preimage resistance on the Hogwarts wards and using that to, say, get a toad credentialed as the Muggle Studies professor. It’d probably do a better job...
...actually, I kind of want to write that now.