Nowadays, most people use password managers (hopefully). However, there are still some passwords that you need to memorize, like master password (for a password manager), phone lock, wifi password, etc.

Security wise, can passphrase reach the strength of a good password without getting so long that it defeats the purpose of even using it?

  • deranger@sh.itjust.works
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    9 months ago

    can passphrase reach the strength of a good password

    Relevant xkcd: https://xkcd.com/936/

    I’d love to hear from someone well versed in security if this is legit or significant weaknesses exist, but the math seems to check out as far as I can tell.

    • Corroded@leminal.space
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      9 months ago

      I feel like you could still run into the issue of dictionary attacks. For example before it brute forces it’s way to the word horse it might just try the word horse.

      • birdcat@lemmy.ml
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        9 months ago

        i also dont really get it. the bitwarden pw tester says it will take 14 years to crack “its.a.beautiful.day”, write beautiful with 2 t`s and it will take “centuries”? 🧐

        but yes i still use them. but always with numbers and random characters in between and words from multiple languages or fantasy words.

        • dzaffaires@sh.itjust.works
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          9 months ago

          That would be because the pattern on the first password are correctly spelled words and the way passwords are cracked offline (when there’s a leak of data being sold somewhere) is that they use dictionary attacks.

          This means that a big file containing all known words, and can also include known used passwords from past leaks, is used to try a lot of combinations. A combination of good words that appear 1:1 in these word lists will score way lower in terms of difficulty for a computer to crack. A simple script can add spaces and periods (like your example) between words and they WOULD get your password. By adding only one random character that doesn’t fit a pattern (just like your second ‘t’), you basically force the cracker to try all possible combinations of all characters for the length of your password, which is WAY more difficult.

          TLDR: There are more combinations of aaaaaaa, aaaaaab, aaaaaac then there are of matching words together for the same length of password (one.one, one.two, one.three)

          • 4am@lemm.ee
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            9 months ago

            In other words, don’t use “correct horse battery staple” because that’s probably in every word list by now

          • birdcat@lemmy.ml
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            9 months ago

            but even 14 years seems long for a pharase that is said and written millions of times per day. and if those crackers can make billions of guesses per second how can they not guess both variants within minutes?

            related question. how to make a good password bettter? adding a few extra special symbols like “µ£₹” or one long word like “freshwatercrocodiletesticles”?

      • NaN@lemmy.sdf.org
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        9 months ago

        Because a hash doesn’t work like a password cracker in a movie. It can try horse, but unless it gets the whole thing correct it doesn’t know any individual part of it.

      • 4am@lemm.ee
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        9 months ago

        If your services are storing passwords properly with a salt, dictionary attacks (including rainbow tables) are just as time-consuming to perform, since the salt renders each password hash unique; even for the same passwords.

        So the same principle still stands; the longer your password, the longer to guess - as long as the encryption-at-rest is done correctly.

      • saigot@lemmy.ca
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        9 months ago

        Dictionary attacks have been around for a long time, but It’s still quite strong especially if you throw in a number.

        A fully random 8 character password has about 10^14 brute force combinations (assuming upper and lower case + the normal special characters). 4 words choosen at random from the top 3000 words (which is a very small vocabulary really) is 10^13 dictionary attack combinations, add a single number or account for variations in word style (I.e maybe don’t always use camel case) and you’ve matched the difficulty. If you use 5 words it’s 10^17 combinations.

        (This is basicly copy pasted from a comment I made earlier)

      • Zagorath@aussie.zone
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        9 months ago

        In the linked comic, Munroe assumes an attacker knows your method. The attacker isn’t brute forcing character-by-character, but word-by-word, with an attacker who already knows you’re using 4 random words.

    • sylver_dragon@lemmy.world
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      9 months ago

      That’s basically a Diceware passphrase. And, it’s kinda ok. The amount of entropy is pretty significant (close to what the comic lists, if the Wikipedia article has it right). And it’s really easy to add more entropy. I often recommend passphrases to my users (I work in Cybersecurity) and use them myself. Take a sentence, with spaces, capitals and punctuation. Now throw in a few numbers for fun and stop worrying about brute force attacks, until some idiot decides unsalted MD5 is perfectly fine for storing passwords. Most such passphrases will blow right past the 4 words in that comic and are very easy to remember. Even better, make that the passphrase for your password vault (oh look a plug for KeePass). Then have the rest of your passwords all be unique, 20 character jumbles of letters, numbers, and special characters.

      Also, enable Two-Factor Authentication (2FA) wherever possible. Even if it’s just a One Time Password (OTP) sent via SMS (which is a shit way to do 2FA), that’s better than no 2FA.

    • foggy@lemmy.world
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      9 months ago

      For what a civilian target would worry about, using sufficiently long passwords is your best defense. Complexity is barely important.

      111111111111111111111111111.1111 is an excellent password.

      Everyone should Ctrl+f their password here. But also wait the 10 minutes it’ll take to load the whole thing.

      If your pw is on this list, change it immediately.

      If it’s less than 8 chars? Change immediately. If it’s less than 10 chars? Change… Now.

      If it’s less than 14 chars, consider just making your password longer.

      This advice will save more people in its simplicity than saying more.


      Want a smidge more?

      If you’re paranoid, take a password that you think is decent, then insert it here, then use the output as your password.

      Most times, pws aren’t stored in plain text, they’re stored using that algorithm. So, if your password is ‘password’, hackers night easily be able to see that your passwords encrypted value is exactly what that link will output if you put in ‘password’. If your password is on that huge list from the beginning of the post, they can easily decrypt the encrypted password, because these passwords’s hashes are known.

      So, use the hash itself as a password.

      Hell, throw a comma at the beginning to throw it off.

      • ∟⊔⊤∦∣≶@lemmy.nz
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        9 months ago

        using sufficiently long passwords is your best defense

        No, using 2FA is your best defense, along with wise recovery questions. It matters nothing if you know someone’s password, but can’t get the 2FA code.