Stack Overflow
Stack Overflow

Questions tagged [elliptic-curve]

In mathematics, an elliptic curve is a smooth, projective algebraic curve of genus one, on which there is a specified point O.

In mathematics, an elliptic curve is a smooth, projective algebraic curve of genus one, on which there is a specified point O (the point at infinity). An elliptic curve is in fact an abelian variety — that is, it is a (necessarily commutative) group with respect to an algebraically defined multiplication — and O serves as the identity element. Often the curve itself, without O specified, is called an elliptic curve.

685 questions
0
votes
1 answer

Javascript convert ECDH keys into ECDSA keys

I generate the ECDH keys in this way let _this = this; window.crypto.subtle.generateKey( { name: "ECDH", namedCurve: "P-256", // the curve name }, true, // <== Here if you want it to be exportable !! …
Vito Lipari
  • 795
  • 8
  • 35
0
votes
1 answer

OpenSSL generates non-deterministic signature on CSR using P-256 or P-384 key, but not RSA key?

When I use openssl's command line to generate an RSA-2048 keypair, and then construct two Certificate Signing Requests (CSRs) for identical domain names using identical private keys, I get identical output. $ openssl genrsa -f4 -out rsa.key | head…
Quuxplusone
  • 23,928
  • 8
  • 94
  • 159
0
votes
0 answers

Scalar Multiplication with a negative number in elliptic curve

I want to implement scalar multiplication in which I have to multiply a point of elliptic curve with a negative number using CRYPTOPP library, but I'm getting an error while doing this. Am I supposed to take the mod of that negative number…
user11543755
0
votes
3 answers

How do I get ECDH keypair in Android 9.0 pie?

I want to get ECDH keypair (Public key and Private key). This method is not working in Android 9.0 pie, because Security provider "BC" , "SC" is removed from this version. I tried below method KeyPairGenerator keyGen =…
Dev Tamil
  • 629
  • 1
  • 9
  • 25
0
votes
1 answer

Implementation of Elliptic Curve Cryptography in C

I'm trying to decrypt a sent set of points (kB, Pm+k.Pb) of an elliptic curve over a prime field. However, I am getting the wrong result. My guess is that something is wrong in point subtraction. Can someone please help? I have followed all the…
Shubham Annigeri
  • 13
  • 1
  • 2
0
votes
1 answer

Exponentiation on a point on elliptic curve unreasonably fast in SageMath

I am working on elliptic curves in sagemath. I was trying to collect benchmarks for group operation and exponentiation of points on NIST P-256 elliptic curve. When I tried to perform a group operation on 2 points on the curve, it takes roughly 2…
satya
  • 469
  • 1
  • 6
  • 14
0
votes
2 answers

calculate public key from private key is not correct

I am using EC curve P-256. I generate a key pair. Then, form the private key, I calculate the public key. For some reason, the two public key values do not correspond. See included code with the function to generate a key pair: public static…
Kobodjo
  • 11
  • 1
0
votes
0 answers

Algorithm of elliptic curve point addition in mixed Lopez Dahab-affine coordinates

In Guide to Elliptic Curve Cryptography, it provides the formulas to calculate the point addition in mixed Lopez Dahab-affine coordinates, as shown follows. In the actual algorithm, The code involves additional conditional statements to handle…
mksit
  • 1
  • 2
0
votes
1 answer

encryption image with ECC in java

I want to encrypt an image with ECC, i tried using Bouncy Castle but it cant encrypt each pixel alone,and i asked about it in another question here in stackoverflow and the Answer was to implement ECC without B**C. So i searched about ECC and…
Chada
  • 3
  • 4
0
votes
1 answer

Web3j ECKeyPair to KeyPair

I'm trying to make an ECC with the generated key using web3j. I have the ECKeyPair object, but cipher.init() requires 2nd parameter to be Key object. ECKeyPair returns BigInteger of private key and public key, how can I convert them to KeyPair which…
Tenten Ponce
  • 2,436
  • 1
  • 13
  • 40
0
votes
1 answer

How to encrypt image with ecc in java

I have to encrypt a bmp image with ECC, but I found it very difficult especially when the pixels will be mapped on the elliptic curve, I didn't understand it at all. So I researched other options and found ECIES. I tried to implement it in java…
Chada
  • 3
  • 4
0
votes
1 answer

elliptic curve point multiplication sometimes yields wrong results

I am trying to implement elliptic curve point with scalar multiplication in Python and have the issue that in some cases I get incorrect results and am struggling to figure out what could be wrong. Here is the function performing the…
Jakob Abfalter
  • 4,980
  • 17
  • 54
  • 94
0
votes
0 answers

Format of EC public key exported from Android Keystore

I am exporting a public key from the Android Keystore with: final byte[] publicKey =((KeyStore.PrivateKeyEntry)entry).getCertificate().getPublicKey().getEncoded(); It works but I cannot figure out what format this exported key is in, Android docs…
Francesco Rigoni
  • 923
  • 7
  • 20
0
votes
1 answer

Elliptic Curve with a secant line

Currently I was trying to solve a problem with the condition below: 1. giving an elliptic curve y^2 = x^3 + ax + b 2. the user will input a, b and two points that exactly on the curve. To put it simply, what I really need to do is make a secant…
Yuta
  • 3
  • 2
0
votes
1 answer

Point addition and multiplication on Sage

I am trying to compute rP+r'Q on Sage where r,r' are positive integers and P=(38*a + 31 : 69*a + 77 : 1), Q=(106*a + 3 : a + 103 : 1) two points on the elliptic curve E:y^2=x^3-x over GF(107^2). Now I tried to define P and Q on sage simply as I…
Smissi
  • 11
  • 4
1 2 3
…
45 46