r/crypto

Why are Montgomery and twisted Edwards curve said to be all quadratic twist secure ?

Simple question. According to SafeCurve, all twisted Edwards and Mongomery curves are quadratic twist secure. But why ?

modular sqrt(Q) in elliptic curves over F, where Q is a point and not an integer?

Join us next week on Thursday, Jan 30th at 2PM CEST for an FHE.org meetup with Philippe C., Senior researcher at Inria, who will be presenting "Homomorphic Sign Evaluation with a RNS Representation of Integers".

Book for introduction to cryptography

I am looking for a book for beginners, explaining all the concepts for key sharing, block and stream ciphers, vulnerabilities, polygons, where primes come in the picture, etc. Possibly supplemented with examples, as well as real-world ciphers and how they …

Do all points of secp256k1 have the same order as standard G's one?

``` G_Coordinates = (0x79be667ef9dcbbac55a06295ce870b07029bfcdb2dce28d959f2815b16f81798, 0x483ada7726a3c4655da4fbfc0e1108a8fd17b448a68554199c47d08ffb10d4b8) ``` and knowing that we are in `x^3 + 7` and knowing that the modulus is ``` p = 0xfffffffffffffffffffffffffffffffffffffffffffffffffffffffefffffc2f ``` than we can calculate the order of point G ``` n = 0xfffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141 ``` …

If Grovers "roots" the bit strength of hash functions/sym crypto, what does shors do to ECC?

I appreciate modern ECC is essentially only as strong as half the bit strength of the curve group (subgroup) due to Pollard's Rho. Given Grovers essentially roots the bit strength of hash functions and symmetric crypto (256->128), what does it …

Looking for encrypted object formats

I'm looking for prior art in encrypted object formats intended for encryption at rest (or store and forward messaging) for objects in the kilobytes to gigabytes range. Most probably involve marshalling together some symmetrically encrypted data along with a metadata …

The best visual representations of elliptic curves on finite fields you are aware of

Hi guys, in few words: my head wraps around visual representations way way way easier than math math models and watching visual presentations (better if they are interactive) makes my knowledge more flexible. I'm aware of the representation of the …

Storing libsodium private keys on disk

Hi everyone, I want to use libsodium in PHP in a little code signing/verifying library I'm writing. I had a working implementation in OpenSSL, but that extension isn't always installed on hosts, where it seems that libsodium mostly is. The …

Excited to share my latest research in Privacy Preserving Authentication technology!

🌟 **Dear Scientists, Researchers, Scholars, and Enthusiasts,** 🌟 I am **thrilled** to announce the pre-print of my latest research paper, now available on the [International Association for Cryptologic Research (IACR) ePrint archive](https://eprint.iacr.org/2024/2066). 📚✨ >**Goal**: To authenticate accurately and securely **without …