ECC - GnuPG wiki

Elliptic curve cryptography (ECC) is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. One of the main benefits in comparison with non-ECC cryptography [..] is the same level of security provided by keys of smaller size. from its Wikipedia entry 2015-11-05

http://arstechnica.com/security/2013/10/a-relatively-easy-to-understand-primer-on-elliptic-curve-cryptography/1/

GnuPG 2.1 supports ECC.

Function	Protocol	Curve	Spec.	Library dependency	Token
Signature	ECDSA	NIST P-256	RFC6637		Gnuk 1.2
Signature	ECDSA	NIST P-384	RFC6637
Signature	ECDSA	NIST P-521	RFC6637
Signature	ECDSA	brainpoolP256r1
Signature	ECDSA	brainpoolP384r1
Signature	ECDSA	brainpoolP512r1
Signature	ECDSA	secp256k1		libgcrypt 1.7	Gnuk 1.2
Signature	EDDSA	Ed25519	draft RFC4880bis		Gnuk 1.2
Encryption	ECDH	NIST P-256	RFC6637		Gnuk 1.2
Encryption	ECDH	NIST P-384	RFC6637
Encryption	ECDH	NIST P-521	RFC6637
Encryption	ECDH	brainpoolP256r1
Encryption	ECDH	brainpoolP384r1
Encryption	ECDH	brainpoolP512r1
Encryption	ECDH	secp256k1		libgcrypt 1.7	Gnuk 1.2
Encryption	ECDH	Curve25519		libgcrypt 1.7	Gnuk 1.2

https://datatracker.ietf.org/doc/draft-koch-openpgp-rfc4880bis/