Talk:936: Password Strength

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You still have to vary the words with a bit of capitalization, punctuation and numbers a bit, or hackers can just run a dictionary attack against your string of four words. Davidy²²[talk] 09:12, 9 March 2013 (UTC)

No you don't. Hackers cannot run a dictionary attack against a string of four randomly picked words. Look at the number of bits displayed in the image: 11 bits for each word. That means he's assuming a dictionary of 2048 words, from which each word is picked randomly. The assumption is that the cracker knows your password scheme. 86.81.151.19 20:17, 28 April 2013 (UTC) Willem

Sometimes this is not possible. (I'm looking at you, local banks with 8-12 character passwords and PayPal) If I can, I use a full sentence. A compound sentence for the important stuff. This adds the capitalization, punctuation and possibly the use of numbers while it's even easier to remember then Randall's scheme. I think it might help against the keyloggers too, if your browser/application autofills the username filed, because you password doesn't stand out from the feed with being gibberish. 195.56.58.169 09:01, 30 August 2013 (UTC)

The basic concept can be adapted to limited-length passwords easily enough: memorize a phrase and use the first letter of each word. It'll require about a dozen words (you're only getting 4.7 bits per letter at best, actually less because first letters of words are not truly random, though they are weakly if at all correlated with their neighbors -- based on the frequencies of first letters of words in English, and assuming no correlation between each first letter and the next, I calculate about 4 bits per character of Shannon entropy). SteveMB 18:35, 30 August 2013 (UTC)

Followup: The results of extracting the first letters of words in sample texts (the Project Gutenberg texts of The Adventures of Huckleberry Finn, The War of the Worlds, and Little Fuzzy) and applying a Shannon entropy calculation were 4.07 bits per letter (i.e. first letter in word) and 8.08 bits per digraph (i.e. first letters in two consecutive words). These results suggest that first-letter-of-phrase passwords have approximately 4 bits per letter of entropy. --SteveMB (talk) 14:21, 4 September 2013 (UTC)

Addendum: The above test was case-insensitive (all letters converted to lowercase before feeding them to the [frequency counter]). Thus, true-random use of uppercase and lowercase would have 5 bits per letter of entropy, and any variation in case (e.g. preserving the case of the original first letter) would fall between 4 and 5 bits per letter. --SteveMB (talk) 14:28, 4 September 2013 (UTC)

I just have RANDOM.ORG print me ten pages of 8-character passwords and tape it to the wall, then highlight some of them and use others (say two down and to the right or similar) for my passwords, maybe a given line a line a little jumbled for more security. 70.24.167.3 13:27, 30 September 2013 (UTC)

Remind me to visit your office and secretly replace your wall-lists by a list of very similar looking strings ;) --Chtz (talk) 13:53, 30 September 2013 (UTC)

Simple.com (online banking site) had the following on it’s registration page:

“Passphrase? Yes. Passphrases are easier to remember and more secure than traditional passwords. For example, try a group of words with spaces in between, or a sentence you know you'll remember. "correct horse battery staple" is a better passphrase than r0b0tz26.”

Online security for a banking site has been informed by an online comic. Astounding. 173.245.54.78 21:22, 11 November 2013 (UTC)

The Web service Dropbox has an Easter egg related to this comic on their sign-up page. That page has a password strength indicator (powered by JavaScript) which changes as you type your password. This indicator also shows hints when hovering the mouse cursor over it. Entering "Tr0ub4dor&3" or "Tr0ub4dour&3" as the password causes the password strength indicator to fall to zero, with the hint saying, "Guess again." Entering "correcthorsebatterystaple" as the password also causes the strength indicator to fall to zero, but the hint says, "Whoa there, don't take advice from a webcomic too literally ;)." 108.162.218.95 15:17, 11 February 2014 (UTC)

The explanation said that the comic uses a dictionary[1]. In fact it's a word list, which seems similar but it's not. All the words in the word list must be easy to memorize. This means it's better not to have words such as than or if. Also, it's better not to have homophones (wood and would, for example). The sentence dictionary attack doesn't apply here. A dictionary attack requires the attacker to use all the words in the dictionary (e.g. 100,000 words). Here we must generate the 17,592,186,044,416 combinations of 4 common words. Those combinations can't be found in any dictionary. At 25 bytes per "word" that dictionary would need 400 binary terabytes to be stored. Xhfz (talk) 21:37, 11 March 2014 (UTC)

This comic was mentioned in a TED talk by Lorrie Faith Cranor on in March 2014. After performing a lot of studies and analysis, she concludes that "pass phrase" passwords are no easier to remember than complex passwords and that the increased length of the password increases the number of errors when typing it. There is a lot of other useful information from her studies that can be gleaned from the talk. Link. What she doesn't mention is the frequency of changing passwords - in most organizations it's ~90 days. I don't know where that standard originated, but (as a sys admin) I suspect it's about as ineffective as most of our other password trickery - that is that it does nothing. Today's password thieves don't bash stolen password hash tables, they bundle keyloggers with game trainers and browser plugins.--173.245.50.75 18:14, 2 July 2014 (UTC)

Just because you are required to have a password that has letters and numbers in it doesn't mean you can't make it memorable. When caps are required, use CamelCase. When punctuation is required, make it an ampersand (&) or include a contraction. When numbers are required, pick something that has significance to you (your birthday, the resolution of your television, ect.). Keep in mind that, if your phrase is an actual sentence, the password entropy is 1.1 bits per character (http://what-if.xkcd.com/34), so length is key if you want your password to be secure. (Though no known algorithm can actually exploit the 1.1 bits of entropy to gain time, so it might be more like 11 bits of entropy per word. Even then, my passwords have nonexistent and uncommon words in them, (like doge or trope), which also adds some entropy.) 108.162.246.213 22:18, 1 September 2014 (UTC)

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