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Generate Memorizable Passphrases That Even the NSA Can't Guess
HughPickens.com writes Micah Lee writes at The Intercept that coming up with a good passphrase by just thinking of one is incredibly hard, and if your adversary really is capable of one trillion guesses per second, you'll probably do a bad job of it. It turns out humans are a species of patterns, and they are incapable of doing anything in a truly random fashion. But there is a method for generating passphrases that are both impossible for even the most powerful attackers to guess, yet very possible for humans to memorize. First, grab a copy of the Diceware word list, which contains 7,776 English words — 37 pages for those of you printing at home. You'll notice that next to each word is a five-digit number, with each digit being between 1 and 6. Now grab some six-sided dice (yes, actual real physical dice), and roll them several times, writing down the numbers that you get. You'll need a total of five dice rolls to come up with each word in your passphrase. Using Diceware, you end up with passphrases that look like "cap liz donna demon self", "bang vivo thread duct knob train", and "brig alert rope welsh foss rang orb". If you want a stronger passphrase you can use more words; if a weaker passphrase is ok for your purpose you can use less words. If you choose two words for your passphrase, there are 60,466,176 different potential passphrases. A five-word passphrase would be cracked in just under six months and a six-word passphrase would take 3,505 years, on average, at a trillion guesses a second.
After you've generated your passphrase, the next step is to commit it to memory.You should write your new passphrase down on a piece of paper and carry it with you for as long as you need. Each time you need to type it, try typing it from memory first, but look at the paper if you need to. Assuming you type it a couple times a day, it shouldn't take more than two or three days before you no longer need the paper, at which point you should destroy it. "Simple, random passphrases, in other words, are just as good at protecting the next whistleblowing spy as they are at securing your laptop," concludes Lee. "It's a shame that we live in a world where ordinary citizens need that level of protection, but as long as we do, the Diceware system makes it possible to get CIA-level protection without going through black ops training."
After you've generated your passphrase, the next step is to commit it to memory.You should write your new passphrase down on a piece of paper and carry it with you for as long as you need. Each time you need to type it, try typing it from memory first, but look at the paper if you need to. Assuming you type it a couple times a day, it shouldn't take more than two or three days before you no longer need the paper, at which point you should destroy it. "Simple, random passphrases, in other words, are just as good at protecting the next whistleblowing spy as they are at securing your laptop," concludes Lee. "It's a shame that we live in a world where ordinary citizens need that level of protection, but as long as we do, the Diceware system makes it possible to get CIA-level protection without going through black ops training."
Diceware is a great recommendation, but you're missing one key consideration: password reuse is a larger danger to users than is having a weak password. The Apple iCloud hack is one of the few in recent memory where a password-related breach wasn't tied to password reuse. What happens most of the time is that a site is vulnerable to SQL injection gets their users table stolen, and "bad guys" use that information to try accounts on related sites. If the compromised website was using a bad (i.e. fast) password hashing algorithm, then having a good password will protect you a little, but you're playing with fire. Password cracking techniques have been advancing exponentially, as has GPU power. But if this site is using reversible encryption or storing passwords in plaintext (which still happens with alarming frequency) then all your other accounts are at risk from the one breach regardless of how great your password is. Of course, if they're using a good password algorithm like PBKDF2 or bcrypt, even a mediocre password will be relatively safe. But what are the chances that every site you've registered with is using a good password algorithm? Probably zero. How can you check the password storing technique of a site you're about to register with? You can't.
Yeah, you could make an algorithm to modify your password across sites so that you can memorize it yet it'll be different, but as "bad guys" combine information from multiple leaks, any algorithm you come up with will be vulnerable to reverse engineering. Especially if your online identity is valuable. The real solution is to use password management software like KeePass, LastPass, or 1Password. Lock your password program with your good password from Diceware, and use unique, truly random passwords for all the websites you've registered on.
What about the sites that restrict the length of the password? The only thing I have to say to them is, "You're doing it wrong".
Many websites, especially those designed to be more secure (banking, education, employment) still require passwords in a certain form (usually requiring some combination of caps, numbers, and special characters) and don't allow passwords like these.
How's that any different from http://xkcd.com/936/?
I thought we were just supposed to use
CorrectHorseBatteryStaple
"A person is smart. People are dumb, panicky dangerous animals and you know it." - K
Exactly the opposite: "Encryption works" was one of the key points made by Edward Snowden. The NSA found it much easier to just bypass encryption. There are some instances where we suspect the NSA has had a hand weakening or backdooring some algorithms (like recommending odd seed values for elliptic curve cryptography) but nothing definitive.
ROT13 is pretty safe, especially if it's used twice.
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I forget where I first read it, but this sounds like a good workaround. Pick a nice secure-as-you-want password. But each website gets a different username. It sounds like most attacks are of the kind "joe_bob uses P4$$word on amazon, let's see if joe_bob uses P4$$word on this banking site too." They don't seem to be looking to see if joe_bob_amazon is the same account as joe_bob_wellsfargo. Or you could be joe_a_bob and joe_wf_bob.
Even better is if you have some control over your email accounts. They are probably smart enough to see joe.bob@gmail is j.o.e.bob@gmail(although that does let you filter incoming mail a little easier). But if you have control over the domain you have a catch all address and be me_amazon@myplace.com and me_wellsfargo@myplace.com.
This procedure assumes fair, unbiased dice. For years, the NSA has required precise machining of dice to generate predictable rolls. Once someone cracks the code, Casinos will lose billions.
What, other than precision machining, would explain why plastic dice with a materials cost of pennies cost over $2/each?
First you claim that they use malware to send my plaintext passwords to themselves. Then you claim they have been caught red-handed doing the first claim...by compromising networking equipment which never sees my plaintext passwords.
I understand your point, but your claims are rather incongruous.
https://xkcd.com/538/
If they can't afford enough computer to crack your passphrase, they can still afford a $5 wrench
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No.
There are 10 digits, there are (in this list) 7.7k dictionary words.
If you tell a hacker "my password is 5 digits" - they have 10^5 keys to test, or 100000.
If you tell them "my password is 5 words" they have 7700^5 keys to test, or 2.7 * 10^19 - which is more than twice as hard to crack as an 19-digit password, which again is 10 trillion times as hard as your 5 digit password.
It's just math, people. You don't have to rely on hand-rules like "dictionary words are bad."
Why would they go through the trouble of reverse enigneering your password system when there's thousands of other people who just use the same exact password everywhere? Unless someone is trying to specifically target you, it's usually sufficient to simply not be the low-hanging fruit. In case of these large password leaks, what they're probably doing is something like this:
1. Take every username (or email) and password combination
2. Through automated means, check if they are valid on other websites
3. Record the ones that worked and abuse/sell those as well.
Yes, "don't outrun the bear; outrun your companion" is a fair strategy in computer security. But if you're made of particularly juicy and delicious man-meats (which would be analogous to having your name be Brian Krebs or Jennifer Lawrence or being a Google employee or having a three letter twitter handle), some bears might decide that it's worth a little extra effort to run you down instead. It's a personal decision as to how much effort you're willing to put into protecting your online identity.
Your first word is 7 digits your second is 3, so clearly one is stronger than the other. "nom" is not in the diceware set, which helps a little, but it isn't so uncommon to be in a search dictionary. The numbers are in the diceware set.
You're comparing 7700^3 against 7700^7. Your more secure password isn't any better than chickensandwichwafflesworkcraigcrossafrica, probably a lot less good because chicken, delicious and nom clearly correlate heavily and nomnomnom is almost one word really. 7700^7 is 1604852326685300000000000000 according to my calculator. If I assume 72 characters (52 letters, 10 numbers, 10 special characters) then I need a 15 character random password to beat it in terms of search space. Maybe this: }&X$0ueUo~ravx&.
Further, if you put numbers between your letters you are turning a search space of 7700 into 7710 or whatever. If you replace l with 1 and so on, you are surely turning 7700 into 7700*(number of replacement options and combinations thereof). So mathematically, I would think that replacing e with 3, a with @ would actually be a stronger encoding that what you suggest.
someone who physically possesses the token has three guesses of my unlocking passphrase before the token locks itself forever and zeroes out the stored keyfile
If fat-fingering your passphrase thrice will make your data permanently inaccessible, then you better have damn good backups and a damn good data plan with which to restore them when and where you need your data.