4 ms·
Isn't P always the same? Or is it shared before the exchange? Edit: just looked it up and the base point for curve25519 is x=9 so no point in recovering it.
by bembo 3y ago
Isn't P always the same? Or is it shared before the exchange?
Edit: just looked it up and the base point for curve25519 is x=9 so no point in recovering it.
- syncsynchalt 3y agoIn modern curves P is set in stone head of time. In the early days of EC you were able to pick a custom base point, and then it was found that this could leak information in various ways. It’s not allowed in modern curves or implementations.
- 1aqp 3y agoSorry, I wrote that comment too quickly. It is close to impossible to recover ka, kb and ka.kb.P, even given A=ka.P, B=kb.P and P.