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Representing SHA-256 Hashes as Avatars

francoisbest.com

61–70 of 75 posts

Re: Representing SHA-256 Hashes as Avatars

#61
OpenSSH's randomart was too visually indistinctive for me so I've patched it to draw TrueColor images of cats. I wanted to actually seed a GAN to generate consistent images, but that turned out to be too much of a bother so I'm just keeping a local cache on a machine. Works nicely for that use-case as I'm able to associate a particular image with a particular location when working at a particular box. Good enough.

https://github.com/ilammy/homebrew-ssh

Re: Representing SHA-256 Hashes as Avatars

#62

The problem with hash avatars in general is that people want to use them for identity verification -- and humans are wired to do so automatically -- but technologically, they cannot provide this. The space of possible avatars (2^256, in this case) is far, far larger than the number of distinct objects that humans can distinguish between. Which means that there will invariably be "collisions:" two avatars that are not…

You might get more milage in if the avatars are unique to the user viewing them rather than identical between users. If the nonce/salt used in generation it itself secure then it'd be phrohibity difficult for adversaries to force a collision without obvious detection, doubly so in communities.

"This is what it would look like if your randomart avatar conceived a child with the repo owner's randomart avatar."

Re: Representing SHA-256 Hashes as Avatars

#63

The problem with hash avatars in general is that people want to use them for identity verification -- and humans are wired to do so automatically -- but technologically, they cannot provide this. The space of possible avatars (2^256, in this case) is far, far larger than the number of distinct objects that humans can distinguish between. Which means that there will invariably be "collisions:" two avatars that are not…

There might not be 2^256 distinguishable objects but maybe someone can come up with 2^16 distinguishable objects and just string 16 of them together. If there is one character off in a string of 40 hexadecimal characters it is hard to notice but that would be easier to detect in a set of 16 symbols.

Memorizing order in a set of 16 similar objects is too difficult for me

Re: Representing SHA-256 Hashes as Avatars

#64

The problem with hash avatars in general is that people want to use them for identity verification -- and humans are wired to do so automatically -- but technologically, they cannot provide this. The space of possible avatars (2^256, in this case) is far, far larger than the number of distinct objects that humans can distinguish between. Which means that there will invariably be "collisions:" two avatars that are not…

You might get more milage in if the avatars are unique to the user viewing them rather than identical between users. If the nonce/salt used in generation it itself secure then it'd be phrohibity difficult for adversaries to force a collision without obvious detection, doubly so in communities.

That's a good idea! Although, it could still potentially backfire for the same reason as scrypt; now if an adversary is able to obtain your nonce, they are much more likely to fool you.

I guess my broader point here (which I neglected to mention in the OP) is that we already have an excellent means of verifying identities: cryptographic signatures. Avatars are fine, but our interfaces need to make it clear that an avatar is just a costume, not a fingerprint. The Hard Problem, as we all know, is tying real-world people (and objects) to virtual-world pubkeys. If we can manage that, the rest is moot.

Re: Representing SHA-256 Hashes as Avatars

#65
post #34

Strange that neither the article nor the comments mention https://gravatar.com/ It hashes the user's email http://en.gravatar.com/site/implement/hash/ and creates an "identicon" from the hash http://scott.sherrillmix.com/blog/blogger/wp_identicon/ or loads a user-defined image.

I discovered robohash from Gravatar actually, but forgot to mention it, thanks for the reminder.

Re: Representing SHA-256 Hashes as Avatars

#66

I still like snowflakes for this: https://levien.com/snowflake-explain.html is a half-finished blog post explaining the motivation and algorithm I came up with. I never did careful user testing, but suspect that the answer would be that some people can reliably distinguish the patterns, others won't be able to. In any case, there are a lot of variations on this "visual hash" idea, including the original fractal one,…

This is a great idea! Trying random ones, I couldn't find two I thought looked confusable.

Try changing just a few letters in the hash. If you change letters at the start, it changes drastically. But letters at the end change just small bits

Re: Representing SHA-256 Hashes as Avatars

#67

Urbit also developed a solution for turning a number into an avatar, although theirs only have 32 bits of entropy, and to be honest there are many that are difficult to tell apart: https://urbit.org/blog/creating-sigils/

these are pretty. Do you have any idea if there is a way to use the library with other data (hashes) other than the Urbit 'names' or what it is?

Re: Representing SHA-256 Hashes as Avatars

#69
post #46

I did this one some time ago, allows custom visual effects using hash and seeded random: https://www.blankjs.com/

Wow, those are beautiful. Starred.

Thanks. I got tired of gravatar, wanted something customizable and to be used not only for avatars.

Re: Representing SHA-256 Hashes as Avatars

#70
How hard would it be to instead generate faces with random facial features? Humans are already hardwired to be able to detect subtle differences between faces.

That would obviously not make it suitable for generating avatars to identify humans, but it would make this really useful to eg identify git commits or hash signatures.

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