The SSH-2 protocol supports more than one key type. The types
supported by PuTTY are RSA, DSA, ECDSA, and Ed25519.
-The PuTTY developers \e{strongly} recommend you use RSA.
-\#{FIXME: ECDSA, Ed25519!}
-\I{security risk}\i{DSA} has an intrinsic weakness which makes it very
-easy to create a signature which contains enough information to give
-away the \e{private} key!
-This would allow an attacker to pretend to be you for any number of
-future sessions. PuTTY's implementation has taken very careful
-precautions to avoid this weakness, but we cannot be 100% certain we
-have managed it, and if you have the choice we strongly recommend
-using RSA keys instead.
-
-If you really need to connect to an SSH server which only supports
-DSA, then you probably have no choice but to use DSA. If you do use
-DSA, we recommend you do not use the same key to authenticate with
-more than one server.
-
\S{puttygen-strength} Selecting the size (strength) of the key
\cfg{winhelp-topic}{puttygen.bits}