Linked Questions

13 votes
3 answers
27k views

Using ECDSA keys for encryption

I know that ECDSA is used for signature only, but I wonder if I can use the public/private Elliptic Curve keys for encryption too. I have ECDSA SSH public keys and I wonder if I can use them to ...
jcea's user avatar
  • 343
14 votes
1 answer
12k views

Why are ed25519 keys not recommended for encryption?

Was wondering why there is no straightforward way of using ed25519 keys for encryption. Then I found this: https://github.com/indutny/elliptic/issues/108 There it is stated that it's unlike RSA not ...
Lenny's user avatar
  • 163
9 votes
2 answers
10k views

Explanation of each of the parameters used in ECC

I'm having a very difficult time finding a clear explanation of the parameters used elliptic curve cryptography. I know for certain that $p$ is the number or order or whatever of the given field that ...
Melab's user avatar
  • 3,655
11 votes
1 answer
5k views

Mapping of message onto elliptic curve and reverse it?

I would like to perform a variant of Elliptic Curve ElGamal in java using the BouncyCastle libraries. I currently face the difficulty of mapping a message $m$ onto the elliptic curve $E_p$. I have so ...
franckysnow's user avatar
8 votes
2 answers
6k views

Are there any elliptic curve asymmetric encryption algorithms?

RSA offers the functionality of encrypting (short messages, or symmetric keys) with a public key, and decrypting with a private key. However, RSA key generation is extremely expensive, especially for ...
hunter's user avatar
  • 3,965
5 votes
1 answer
1k views

EC ElGamal versus static+ephemeral ECDH

A client application needs to encrypt a UDP datagram for a server with known EC public key $P$. Performing a full ECDH key exchange would defeat the benefit of using UDP as a connectionless protocol. ...
Kai Elvin's user avatar
5 votes
1 answer
929 views

ElGamal with elliptic curves II

There is an encryption scheme using elliptic curves given by @tylo explained here: @tylo's answer on ElGamal with elliptic curves and here: ElGamal with elliptic curves I. The encryption idea is to ...
user45323's user avatar
  • 145
2 votes
1 answer
2k views

ElGamal with elliptic curves I

It is very interesting to see @tylo's answer on ElGamal with elliptic curves. Instead of mapping the message to the elliptic curve point it just reduces an elliptic curve point to its $x$ coodrinate. ...
user11926's user avatar
3 votes
1 answer
2k views

Elliptic curve ElGamal with homomorphic mapping

I am interested in ElGamal due to the fact that you can achieve some degree of homomorphic properties. I became interested in applying ElGamal to elliptic curves, and found this other question with an ...
tolstikh's user avatar
4 votes
1 answer
1k views

ECC - ElGamal with Montgomery or Edwards type curves (curve25519, ed25519) - possible?

I know the usual way of using getting shared secrets for encryption with ECC is DH, however, this only works with two keypairs of exactly the same kind, for example two curve25519- or two p256-...
namerequired's user avatar
1 vote
1 answer
1k views

Using ECDH for encryption and decryption [duplicate]

I'm playing with cryptography and its use with typescript on one side and PHP on the other side. Now I'm looking for routines that can encrypt and decrypt with ecdh's private and shared keys. Any ...
Ritchie's user avatar
  • 11
2 votes
2 answers
272 views

Zero secret key in EC ElGamal: standards vs theory

I'm a bit confused by the standards and some replies regarding zero (the point at infinity) in elliptic curves ElGamal. TL;DR: Why do some people recommend excluding zero? It has nothing to do with ...
pintor's user avatar
  • 558
1 vote
1 answer
680 views

Asymmetrically encrypt a short message into a short string

I have a string whose size is < 32 characters from the following limited character set. uppercase and lowercase Latin letters: A to Z and a to z digits: ...
Xavier's user avatar
  • 13
2 votes
1 answer
394 views

ElGamal on elliptic curves attack model (CPA,CCA1,CCA2)?

I can't find relevant literature discussing three attack models of the ECC-ElGamal algorithm (CPA, CCA1, CCA2) ECC-ElGamal algorithm: ElGamal with elliptic curves I only know that ElGamal belongs to ...
Hung LI's user avatar
  • 31
2 votes
1 answer
304 views

Encrypt with elliptic curves [closed]

The last days I was looking for a way to encrypt using ECC, without having to make the program myself. I was sure that someone should have done it for everyone by now. The best approach I had was ...
Silkking's user avatar
  • 123

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