- DSA is deprecated in OpenSSH 7.0
- ECDSA is not supported by GNOME Keyring.
- Ed25519 is not supported by GNOME Keyring.
Via SSH Keys, in Arch Linux Wiki
- OpenSSH 7.0 deprecated and disabled support for DSA keys due to discovered vulnerabilities, therefore the choice of cryptosystem lies within RSA or one of the two types of ECC.
- As of July 10, 2015, GNOME Keyring does not handle ECDSA and Ed25519 keys. Users will have to turn to other SSH agents or stick to RSA keys.
- These keys are used only to authenticate you; choosing stronger keys will not increase CPU load when transferring data over SSH.
Via How to save an SSH key passphrase in gnome-keyring? in Stack Exchange for Unix & Linux