CRYPTO NEWS

The death of Isogeny based cryptography?

Wouter Castryck and Thomas Decru recently broke SIDH.

From the abstract:

"We present an efficient key recovery attack on the Supersingular Isogeny Diffie-Hellman protocol (SIDH), based on a "glue-and-split" theorem due to Kani."

Related Kani’s work is:

Ernst Kani, The number of curves of genus two with elliptic differentials, Journal f ̈ur die
reine und angewandte Mathematik 485, pp. 93–121 (1997), available at https://www.mast.
queensu.ca/~kani/papers/numgenl.pdf

I have two questions:

1- Does it mean the end of isogeny based cryptography?

2- Why so late? 1997 to 2022?

How does SegWit reduce transaction size, when the signature is simply moved to another part of the transaction?

This video explains that the signature is moved out of the input section and moved to the new one called the witness. From what I can tell, the witness signature is still contained in this transaction – how would a simple reordering of information magically create more space? I’ve perused other articles and videos and ::Listen

This video explains that the signature is moved out of the input section and moved to the new one called the witness. From what I can tell, the witness signature is still contained in this transaction – how would a simple reordering of information magically create more space?

I’ve perused other articles and videos and none of them seem to address this “magic”.

Crypto Hats, Crypto Shirts, Crypto Socks, Crypto Clothing