On Sat, Dec 26, 2015 at 12:34 PM, Owen DeLong <o...@delong.com> wrote: >> On Dec 26, 2015, at 08:14 , Joe Abley <jab...@hopcount.ca> wrote: >> On Dec 26, 2015, at 10:09, Stephen Satchell <l...@satchell.net> wrote >>> My gauge is volume of obnoxious traffic. When I get lots of SSH probes >>> from a /32, I block the /32. [...] >> With respect to ssh scans in particular -- disable all forms of >> password authentication and insist upon public key authentication >> instead. If the password scan log lines still upset you, stop logging >> them. > > This isn’t a bad idea, per se, but it’s not always possible for the guy > running the server > to dictate usage to the people using the accounts. > > Also, note that the only difference between a good long passphrase and a > private key is, > uh, wait, um, come to think of it, really not much. > > The primary difference is that nobody expects to have to remember a private > key so we don’t > get fussed when they contain lots of entropy. Users aren’t good at choosing > good long secure > passphrases and the automated mechanisms that attempt to enforce strong > passwords just > serve to increase user confusion and actually reduce the entropy in passwords > overall.
No, the difference is that a passphrase works in conjunction with the private key, which is the "something you have" vs the "something you know" in two-factor authentication. With password authentication, there's only a single solution space for the attacker to sift through; with private key authentication, unless you're sloppy about securing your private key, there's two massive solution spaces for the attacker to sift through to find the unique point of intersection. Massively different solution space volumes to deal with. Equating the two only has meaning in cosmological contexts. > Owen > Matt