By the account. 3 failed login attempts in a row, and you disallow further logins for 30 seconds.
This should waste less time than reCAPTCHAs. I know it's not 1:1 in terms of pros/cons, but it gets a good subset of the advantages without the key disadvantages mentioned above.
This should waste less time than reCAPTCHAs. I know it's not 1:1 in terms of pros/cons, but it gets a good subset of the advantages without the key disadvantages mentioned above.