Known risks for publishing ECDSA public keys and signatures For an implementation of ECDSA, I'm considering the risks of publishing public keys together with multiple signatures.

From what Google tells me, a common pitfall is the use of the same random value K for multiple signatures.

My question is; are there any other known risks, or common mistakes, regarding the publishing of multiple signatures from one keypair?
ECDSA is advertised to prevent existential forgery even in the face of an adaptive chosen-message attack.  That is: even if the adversary can control the messages you sign, not just see a few signatures, they still can't find a single message/signature pair for a message they didn't ask you to sign.

As part of your obligations of the ECDSA security contract, of course, you must choose the per-signature secret $k$ independently and uniformly at random; if you fail to do this—if you repeat the per-signature secret, or if your choice of it is even substantially biased—then you might leak the private key.  RFC 6979 defines a way to derive the per-signature secret by a pseudorandom function of the message under the secret key, which obviates the need for an entropy source at signing time—or at least mitigates a broken one.

But you could also just use Ed25519, which has this design built-in so you never need to worry about an entropy source at signing time, and has a clearer security story, and is an all-around better design.