Re: [PATCH] mpi:ec: Least leak with k^(-1) for ECDSA.
NIIBE Yutaka via Gcrypt-devel <[email protected]> Fri, 16 May 2025 09:48:05 +0900
| Newsgroups | gmane.comp.encryption.gpg.libgcrypt.devel |
|---|---|
| Message-ID | <[email protected]> |
Jacob Bachmeyer <[email protected]> wrote: > I note from the diff context that the next step after the part you are > changing is to remove a blinding factor from the result. Could be. Currently, my focus is the leaks of K and K^(-1). Blinding here is for the private key (ec->d). > If the calculation is performed blinded, why is least-leak important > enough here to justify the added code complexity? The patch I sent is for K^(-1). (The code would be looked complex, but actually the execution code path is simpler than the one by mpi_mulm. We don't have mpi_mulm_lli or mpi_mul_lli yet.) --