[Solved]: Weak hashing function for memorable IPv6 addresses

Problem Detail: 

IPv6 addresses in the form of 862A:7373:3386:BF1F:8D77:D3D2:220F:D7E0 are much harder to memorize or even transcribe than the 4 octets of IPv4.

There have been attempts to mitigate this, making IPv6 addresses somehow more memorable.

Is there an intentionally-weak hashing function which could be reversed to find that the phrase, say, "This is relatively benign and easy to spot if the phrase is bent so as to be not worth paying" would hash to a target IPv6 address? The hash would, of course, have many colliding inputs to choose from, and a potentially more memorable sentence, such as this example phrase, could be automatically offered.

I guess there are two parts: First a weak hash with good distribution in both directions. Second is an algorithm for selecting memorable phrases from among the many collisions (short, consisting of words from a specified language, perhaps even following a simplified grammar).

Although the hash function would need to be weak, I don't doubt that the effort is still significant - however, once the phrase is known, the computation of the hash to the target address is very quick.

EDIT

I found this related idea, Piphilology, for memorizing some digits of π:

How I wish a drink, alcoholic of course, after the heavy lectures involving quantum mechanics!

Asked By : Jason Kleban

Answered By : TLW

Take the IP address and a wordlist. Then turn the IP address into a list of words from the wordlist based on the digits of the address, base {length of wordlist}.

So, for instance, taking the diceware wordlist and your example, I get: 862A:7373:3386:BF1F:8D77:D3D2:220F:D7E0 -> mew hades cup viii 72 grit photo pick raid dey (or potentially the other way around, and/or padded on the other end).

Note this isn't lossy. Although you can relatively easily apply any lossy techniques to this. You may just wish to truncate the IP address, or only select every second bit or something before running it through this mapping.

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Question Source : http://cs.stackexchange.com/questions/2752