Dan Boneh's intro cryptography course is excellent.[0] The closest to a Khan Academy "cryptography edition" one can find.<p>0. <a href="https://www.coursera.org/learn/crypto" rel="nofollow noreferrer">https://www.coursera.org/learn/crypto</a><p>PS: I must be old because I can't get past the neologism of "crypto" abused to mean "crypto<i>currency"</i> rather than "crypto<i>graphy."</i>
> Chia replaces Nakamoto’s energy hungry proof-of-work consensus with an
eco-friendly proof-of-space.<p>Don't be fooled, proof-of-space will eat up SSDs like no tomorrow and you're still hoarding HDDs for little gain.<p>Proofs of space prove that you're storing some useless data. Typically you use HDDs to store the useless data, but to prepare such a HDD you need an SSD. The setup process will perform so many writes that the SSD will be garbage very soon.
Hmm,<p>Daniel Bernstein was only 24 when he bought the first of the Bernstein v. United States series to the courts.<p><a href="https://en.wikipedia.org/wiki/Bernstein_v._United_States" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Bernstein_v._United_States</a><p>Nice work there.<p>( connection being <i>Verified fast formulas for control bits for permutation networks</i> by djb<p><a href="https://cr.yp.to/papers/controlbits-20200923.pdf" rel="nofollow noreferrer">https://cr.yp.to/papers/controlbits-20200923.pdf</a> )
If you're looking for a proof that the Benesh network can implement any permutation (of size 2^n):<p><a href="https://eng.libretexts.org/Bookshelves/Computer_Science/Programming_and_Computation_Fundamentals/Mathematics_for_Computer_Science_(Lehman_Leighton_and_Meyer)/02%3A_Structures/10%3A_Communication_Networks/10.09%3A_Benes_Network" rel="nofollow noreferrer">https://eng.libretexts.org/Bookshelves/Computer_Science/Prog...</a><p>The proof is not super complicated, but it for sure isn't trivial.
For anyone who cares, Beneš network was invented by Václav Beneš, son of the former president of Czechoslovakia Edvard Beneš <a href="https://en.wikipedia.org/wiki/Edvard_Bene%C5%A1" rel="nofollow noreferrer">https://en.wikipedia.org/wiki/Edvard_Bene%C5%A1</a>
It's interesting that the author feels the need to justify why this would be useful in practice. I can imagine this could be useful in many contexts - and regardless, I'd be content for this to just be a purely academic exercise.