GnuPG: How to create ECDSA signature?

Question

https://www.rfc-editor.org/rfc/rfc6637 defines ECDSA for OpenPGP and https://wiki.gnupg.org/ECC lists elliptic curve support in GnuPG since version 2.1

I have version 2.2.25 and it lists ECDSA as supported algorithm:

$ gpg --version
gpg (GnuPG) 2.2.25-unknown
libgcrypt 1.8.7
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <https://gnu.org/licenses/gpl.html>
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Home: /c/Users/Matthias/.gnupg
Supported algorithms:
Pubkey: RSA, ELG, DSA, ECDH, ECDSA, EDDSA
Cipher: IDEA, 3DES, CAST5, BLOWFISH, AES, AES192, AES256, TWOFISH,
        CAMELLIA128, CAMELLIA192, CAMELLIA256
Hash: SHA1, RIPEMD160, SHA256, SHA384, SHA512, SHA224
Compression: Uncompressed, ZIP, ZLIB, BZIP2

However, if I generate a key, I'm not presented with that option:

$ gpg --full-generate-key
gpg (GnuPG) 2.2.25-unknown; Copyright (C) 2020 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
  (14) Existing key from card
Your selection?

How do I generate an ECDSA signature using GPG?

score 5 · Accepted Answer · answered Feb 26 '21 at 08:40

okay, seems one has to add the --expert flag:

$ gpg --full-generate-key --expert                                                    gpg (GnuPG) 2.2.25-unknown; Copyright (C) 2020 Free Software Foundation, Inc.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.

Please select what kind of key you want:
   (1) RSA and RSA (default)
   (2) DSA and Elgamal
   (3) DSA (sign only)
   (4) RSA (sign only)
   (7) DSA (set your own capabilities)
   (8) RSA (set your own capabilities)
   (9) ECC and ECC
  (10) ECC (sign only)
  (11) ECC (set your own capabilities)
  (13) Existing key
  (14) Existing key from card
Your selection? 9
Please select which elliptic curve you want:
   (1) Curve 25519
   (3) NIST P-256
   (4) NIST P-384
   (5) NIST P-521
   (9) secp256k1
Your selection?

GnuPG: How to create ECDSA signature?

1 Answers1