You can create your own dice word list by selecting 7776 words and indexing them with a base-6 ID.
Passphrases You Can Memorize That Even the NSA Can’t Guess
31–40 of 57 posts
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#32I've tested the passphrase: password password password password and most of the online entropy checkers[1] says it's really safe to use such .. is this true? 1. http://rumkin.com/tools/password/passchk.php
Entropy checkers are based on a faulty premise and are always at a disadvantage compared to the state of the art in password cracking. Online security would be in a better place if they had never been invented at all.
The only way to guarantee the entropy of a passphrase is to generate it from a source of high quality randomness (e.g. a CSPRNG or by actually rolling dice, hence the name "Diceware"). Diceware-style passphrases simply balance this requirement with usability by optimizing for things humans are typically good at memorizing (strings of words).
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#33Earlier quoted context omitted.
The entropy checker doesn't know about externalities like how common a word is or how likely it is to appear following some other word or how frequently it's used in passwords specifically. It's just measuring the length of the string, and probably the class from which its characters are drawn (in your case lowercase letters and spaces). Relevant Dilbert: http://dilbert.com/strip/2001-10-25
my point was using some common word on purpose, expecting it to produce a low entropy result My thinking was that "Correct Horse Battery Staple" had more entropy than: "go go go go go go go go go go go go go" .. which, apparently, is not
An online entropy checker is going to assume all the decisions that went into making the password, beyond the ones it's been programmed to understand, were die rolls. This is a false assumption unless, of course, those decisions actually were die rolls. It's generally going to tell you passwords are stronger than they are -- sometimes a LOT stronger.
A password from the space of "things users think up while staring at a dialog box for 5 seconds" has a much different probability distribution than "random strings". There are common passwords, and that's an exploitable pattern, but recognizing those patterns is difficult. All the typical entropy checker is going to tell you is how strong the password would be if it were a random string.
Any pattern is, in principle, exploitable. If I use ten digits of pi as a password, a programmed entropy checker isn't going to know that's easier to guess than ten random digits unless it has been told that, and including all possible exploitable patterns would require rather better software than can currently be written.
So don't trust the results too much.
What you really want to know with passwords is, "Is there outside information that would make this easy to guess?" Does it conform to some external, independent pattern, or are all the patterns in it things you made up after seeing the password itself?
That is why I am a big advocate of random generation as the only safe way to make passwords. Knowing the strength of a password is the same thing as knowing the size of the class of live probabilities from which it's drawn, and to do that you have to characterize the method used for generating it.
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#34I can't imagine doing this for the hundreds of passwords in my list, especially when I change some of them regularly. It could be useful for a master password, though - such as the one that secures my password list. Isn't just remembering a line from a song a little easier? Then you get a password recovery mechanism too, as long as you remember the song, or at least the artist!
A line from a song is far weaker entropy-wise due to grammar. I wonder by how much. Common songs/writings would be vulnerable to a dictionary type attack. As for the hundreds of passwords in your list, I'm convinced a password manager with a master password/3rd party auth/dongle is the way to go. Otherwise it's impossible to have unique passwords for all sites, rotate them, and remember them. Of course the risk is of…
> A line from a song is far weaker entropy-wise due to grammar.
Interesting observation, the usual objection is due to the reduced Kolmogorov complexity which is difficult to quantify. Let's look at a modified diceware scheme of the form:
Article adjective noun adverb verb adjective noun
A (non-random) example might be: The young boy really likes video games.
I'm not going to go through the diceware word list and classify each word, but assuming it is (or could be made) 50% nouns, 25% adjectives, 14% verbs, 11% adverbs and four articles you'd get roughly: 2 bits + 11 bits + 12 bits + 10 bits + 10 bits + 11 bits + 12 bits = 68 bits, which is the equivalent to a 5.2 word normal diceware password. Most of that reduction comes from the article.
Here's a random example made with a diceware generator:
an straw scrim ne adorn drab sybil
I'm not sure that's any easier to memorize.
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#35Earlier quoted context omitted.
Be careful that your "memorability" pruning doesn't reduce the entropy too much.
You just increase the entropy by adding characters, numbers, etc and keeping it reasonably long (20+ chars). The entropy of my passwords is quite high according to Keepass.
The thing is, you can't determine "entropy" of a password after the creation. It's the creating process that determines how "random" your password is. KeePass's measure is just an approximation, and I have no idea about how accurate it is.
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#36Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#37FreeBSD has an odd dictionary file (/usr/share/dict/web2a) which has short phrases. I use a script to randomly pull some entries from it and then I piece memorable ones together to make my passphrase. Sprinkle in some punctuation and character replacement and it makes great passwords that are easy to remember. % ./passphrase.pl 10 coppice-topped belly-naked bastard locust tree diamond bort middle-aged self-mapped air…
Not that odd. All the words from Webster's are in web2, all the compound entries (not strictly "words") are in web2a.
That said, "straight-fibered four-way cock" is my new favorite passphrase.
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#38Their are two levels of security, Mossad and non-Mossad. Worrying about evading the NSA is premature optimization at best and a form of mental illness at worst.
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#39How many easy-to-remember words are there in English, does anyone happen to know? Does Diceware's list include almost all of them?
By 'easy-to-remember', I mean for 99% of the world's English speaking population (i.e., for a widely used application).
I'm trying to estimate the entropy of random, easy-to-remember words. I'm not trying to generate a list (which would vary by region and country).
Re: Passphrases You Can Memorize That Even the NSA Can’t Guess
#40This is actually pretty cool. From the article: Not too bad for a passphrase like “bolt vat frisky fob land hazy rigid,” which is entirely possible for most people to memorize. Compare that to “d07;oj7MgLz’%v,” a random password that contains slightly less entropy than the seven-word Diceware passphrase but is significantly more difficult to memorize. At one trillion guesses per second — per Edward Snowden’s January…
Is the one trillion guesses per second with or without the key-stretching (hashing the master password N number of times)?