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Topic: Use of countries to grab more entropy for brain wallets (Read 3484 times)

sr. member
Activity: 461
Merit: 251
See http://dl.acm.org/citation.cfm?id=2335366 for recent research on passphrase usability; results do not look good.
So to summarize, system-assigned pronouncable passwords should be used over system-assigned passphrases because the latter offers offer no memorizability advantage, and the former is more easily transcribable?

Is anybody here familiar with FIPS 181, and know by how much the pronounceability requirement lowers the entropy?  Is it safe to assume it's negligible (as KeePassX would suggest by giving the same entropy values for pronounceable and non-pronounceable passwords of the same length)?
As a first attempt at pronounceable "words", you can simply alternate between randomly generated consonants and vowels.  For easiest transcribability and memorizability, I figure they should be limited to 3 syllables, i.e. 7 letters and starting/ending with consonants.  Allowing the first letter to be capitalized means five 7-letter words have 5*log2(2*21*5*21*5*21*5*21) ~ 128 bits of entropy.  Example:

Code:
tasoved Lodimut dafogum Dukukap xujinov

I may not remember this unless I'm using it frequently, but I could transcribe it with a pen or a keyboard really easily.  And the paper suggests this is the best we're going to be able to do regarding memorizability, and writing it down usually happens anyway.  So why not also make transcribability a priority?

Example using the more sophisticated FIPS 181 standard:
Code:
Chrawjo Odimgig gotitio Udruevi Cepshuj

NB: If FIPS 181 manages to stuff more entropy into each of these words than I did above, then this can be made more compact.  I have no idea about this.

Edit: I just realized the code I used in the first example left out c, h, q, and y, so the passphrase only had ~ 122 bits of entropy.
legendary
Activity: 1222
Merit: 1016
Live and Let Live
what you need is a password form with auto-complete.  So you start typing the word, and it will give suggestions, then press to auto-complete that word.

Maybe have flag icons, and little pictures, that show up also.

(all this should be disabled, maybe with a 'hide my password' option also.)
legendary
Activity: 1222
Merit: 1016
Live and Let Live
what you need is a password form with auto-complete.  So you start typing the word, and it will give suggestions, then press to auto-complete that word.
sr. member
Activity: 461
Merit: 251
See http://dl.acm.org/citation.cfm?id=2335366 for recent research on passphrase usability; results do not look good.
So to summarize, system-assigned pronouncable passwords should be used over system-assigned passphrases because the latter offers offer no memorizability advantage, and the former is more easily transcribable?

Is anybody here familiar with FIPS 181, and know by how much the pronounceability requirement lowers the entropy?  Is it safe to assume it's negligible (as KeePassX would suggest by giving the same entropy values for pronounceable and non-pronounceable passwords of the same length)?
legendary
Activity: 1652
Merit: 2301
Chief Scientist
See http://dl.acm.org/citation.cfm?id=2335366 for recent research on passphrase usability; results do not look good. http://scholar.google.com/scholar?q=passphrase to see what other researchers have tried.
hero member
Activity: 763
Merit: 500
It still has the full 128 bits of entropy.
shannon != kolmogorov. e.g. "the first 128 digits of pi" has a high entropy but isn't very complex. you really don't know what the next 10-20 years will bring.
sr. member
Activity: 461
Merit: 251
Just lay off this problem. It tends to become a paranoidal obsession, similar to the one exhibited in other thread where very intelligent people assume that Internet is operational but all sources of time are compromised.
Haha, good advice.  I learned it the hard way.

I figured I'd do something similar: build a directed graph with adjectives and nouns as the nodes, and increment the weight of a directed edge from an adjective to a noun whenever the adjective was found preceding the noun in a sentence while scanning through a huge pile of text, e.g. Project Gutenberg.  Then I ranked the adjectives by their weighted degree and pruned all but the top A adjectives from the graph.  Then I ranked the nouns by weighted degree and pruned all but the top N = 2^(128/6) / A nouns.  Then any 6 randomly chosen pairs would give 128 bits of entropy.

Turned out to be a lot of work, and didn't seem to be yielding anything that was much better than ThomasV's solution.
legendary
Activity: 1708
Merit: 1066
@2112 - yes - will have to look at IMEs a bit more closely.

RE: Irish heritage - our family found out recently that we are all eligible for Irish passports (in addition to UK ones) so are all applying!


@FreeMoney - yes I think the variability of countries over time means this idea is a non-starter.
legendary
Activity: 2128
Merit: 1073
@2112 - my brother has taken our family tree back a couple of centuries and we are completely UK+Irish. :-)

On your point on IMEs - from Java's point of view this is mainly in the OS and Java *should* pick up any unicode text that is put into any text field. (Java understands unicode natively)

From your post - are you saying this is NOT the case ? I.e can you not use the IME you normally use for Chinese/ Korean/ whatever ? If so, I need to look into that.
I haven't tried your software in a long while. But I do have plentitude of general experience with Java (and other languages supposed to use Unicode natively). One of the most common errors are related to incorrectly supporting the "supplementary characters", the ones beyond the "base plane" of 64kilo-characters.

As to your Irish heritage: one of the best scenes in the movie "The Guard" is where Irish people cooperate with the police by speaking Gaelic. Talk about sufficient entropy...
legendary
Activity: 1246
Merit: 1016
Strength in numbers
Imagine if you had "Siam" in your password and then one day it was gone!
legendary
Activity: 1400
Merit: 1013
The biggest concern I have with using a brain wallet is chance of forgetting the passphrase.

In order to get high entropy you needs a unique phrase that does not appear anywhere in media, literature or popular culture. How easy is that to remember for long periods of time, especially if you don't compromise security by writing it down? Surely no one would use a brain wallet for addresses which they frequently withdraw from, so how would one remember a random set of words accurately across a period of years?
legendary
Activity: 1708
Merit: 1066
@2112 - my brother has taken our family tree back a couple of centuries and we are completely UK+Irish. :-)

On your point on IMEs - from Java's point of view this is mainly in the OS and Java *should* pick up any unicode text that is put into any text field. (Java understands unicode natively)

From your post - are you saying this is NOT the case ? I.e can you not use the IME you normally use for Chinese/ Korean/ whatever ? If so, I need to look into that.
legendary
Activity: 2128
Merit: 1073
Good advice there 2112!

:-)

I am not really monolingual no. Whilst my mother tongue is English I speak reasonable Spanish and have lived in Germany and China.
Thank you very much for not getting offended. I wrote my post above with trepidation that somebody will start another deletion campaign against my posts.

If anyone is worried about the entropy of your password/passphrase/passpoem: just make friends with people speaking other languages or at the minimum research the roots of your family. Who knows, you may really be 1/16 Navajo?
vip
Activity: 1386
Merit: 1140
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
Country names are not a good choice because they become obsolete. No-one talks anymore about Ceylon, Bechuanaland, Rhodesia, Siam etc anymore - yet these country names were all in use when I was at school.

I guess names of food items aren't a good choice either because food spoils?
legendary
Activity: 1708
Merit: 1066
Good advice there 2112!

:-)

I am not really monolingual no. Whilst my mother tongue is English I speak reasonable Spanish and have lived in Germany and China.
legendary
Activity: 2128
Merit: 1073
Do people think this is an easier way to remember 128 bits?
Jim, are you, by chance, a monolingual person? Are you capable of reading any other script than Latin?

Just lay off this problem. It tends to become a paranoidal obsession, similar to the one exhibited in other thread where very intelligent people assume that Internet is operational but all sources of time are compromised.

As far as your software: just make sure that Unicode and various Input Method Editors are operational.

Really just lay it off for a while: it isn't a technical issue and really a behavioral health issue.
legendary
Activity: 1708
Merit: 1066
Good point. And they do not even rename 1-to-1. e.g. Sudan -> North Sudan + South Sudan.
donator
Activity: 826
Merit: 1060
Country names are not a good choice because they become obsolete. No-one talks anymore about Ceylon, Bechuanaland, Rhodesia, Siam etc anymore - yet these country names were all in use when I was at school.
legendary
Activity: 1708
Merit: 1066
It still has the full 128 bits of entropy.

The 6 'concrete words' list is shorter and hence easier to remember.

Then each 'concrete word' you visualise in a country specific setting which is the sort of thing humans are good at.

Try it yourself - it is a lot easier than trying to remember:

1101101101010011101110111011100010100101010101110001011001110101011011011010100 111011101110101000101001000101011100010110111101010

(that should be 128 bits!)

hero member
Activity: 763
Merit: 500
if it is easy to remember, by any standards, it's poor. that's basically a by-product of the kolmogorov complexity.

nobody knows how good word-based attacks will work in 10 years, hence better don't rely on such simplifications.
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