Trevor Perrin <[email protected]> writes: > Some crypto apps let users inspect the public-key hash (aka > "fingerprint") of the other party, so that it can be compared with a > value received through a different channel (phone call, business card, > online directory or website, etc.) > > There's a lot of variation in how public-key fingerprints are > presented (alphabet, number of chars, capitalization, grouping, > separators, etc). For example: > > SSH: 43:51:43:a1:b5:fc:8b:b7:0a:3a:a9:b1:0f:66:73:a8 > > GPG: 7213 5CAA EA6B 0980 126A 0371 8373 DD15 4D42 48BD > > OTR: C4E40F71 A92175F8 597A29A7 CB7E0943 B27014FF > > TACK: g5p5x.ov4vi.dgsjv.wxctt.c5iul > > Bitcoin: 31uEbMgunupShBVTewXjtqbBv5MndwfXhb > > > SSH: 128 bits, 32 hex chars > GPG: 160 bits, 40 hex chars > OTR: 160 bits, 40 hex chars > TACK: 125 bits, 25 base32 chars (RFC 4648) > Bitcoin: 200 bits, 34 base58 chars (160 bits hash + version/checksum) > > There's also some fingerprint innovations that aren't widespread: > - Zooko's z-base32 > - "Hash extension" from RFC 3972 to squeeze more bits into a smaller > fingerprint > - Phonetic alphabets like the PGPfone wordlist > > Anyways, these are somewhat large strings for users to handle, so it > seems worth trying to streamline the experience and reduce error-rates > due to soundalike or lookalike characters as much as we can. > > I'm a little surprised I can't find more useability research here, except for: > - https://blog.crypto.cat/2014/01/cryptocat-at-the-openitp-dc-hackathon > - https://moderncrypto.org/mail-archive/curves/2014/000011.html > > Are there other studies? Are there any "best practices" emerging? >
Hm. You might find some interesting references in the paper that introduced the SSH "randomart" scheme. The paper is called "Hash Visualization: a New Technique to Improve Real-World Security" and contains a bunch of interesting ideas. I agree with you that the UX of public-key validation can be improved vastly. The comment on the cited cryptocat blog post about the word "fingerprint" terrifying users is also interesting. _______________________________________________ Messaging mailing list [email protected] https://moderncrypto.org/mailman/listinfo/messaging
