A passphrase is a longer password that typically consists of multiple words.

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If I enter a password on the wrong site, should I consider it compromised?

I have recently started to make use of a password manager and good password practices. I have a different password for each site that I use. If I accidentally use the password from another site when ...
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Pre-hash password before applying bcrypt to avoid restricting password length

Good practice is not to unnecessarily restrict password length, so that appropriately-long passphrases (perhaps 35-45 chars for 6/7 dicewords) can be used. (See e.g. Should I have a maximum password ...
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Is it possible for my password to have more than one password combination?

Can my password have more than one password combination? I read up on physical combination locks (the lock you open with numbers) and I learned that a combination lock can have about 40 or more ...
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1answer
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Can a dictionary attack crack a Diceware passphrase?

Everyone knows the words used in Diceware passwords (all 6^5 = 7776 words are published) -- they're all common words. Everyone seems to know that we're not supposed to use dictionary words for ...
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Would turning a Diceware phrase into a sentence decrease its security?

Diceware passphrase lengths are on the rise - up to six or seven words now. The old adage that passphrases are easier to remember may be true for shorter phrases, but six truly random words can be ...
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What's the advantage of using PBKDF2 vs SHA256 to generate an AES encryption key from a passphrase?

I'm looking at two comprable pieces of software which need to encrypt data on disk using a passphrase. One uses PBKDF2 to generate the encryption key from a passphrase, while the other uses two rounds ...
19
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5answers
710 views

What concrete parameters can I change to make my passphrase-protected private gpg key more secure

There are several questions which discuss the resistance of passphrase-protected private gpg keys against brute force attacks. It seems, this kind of discussion could go on forever. Rather than ...
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Is a passphrase-protected SSH private key susceptible to a dictionary attack?

If I have a passphrase-protected SSH private key, AND if this passphrase is sufficiently random and long (say, 20-, 30-, 40-characters long, or even more!), AND if I make this private key of ...
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How does correct grammar affect password security?

When using the XKCD password methodology, entropy is calculated solely on the basis of individual words, assuming that the individual words are independent. This is, of course, not necessarily a valid ...
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5answers
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Is it possible to recover a lost passphrase for a private key file?

We have a set of public and private keys and certificates on the server. The problem is that while public encryption works fine, the passphrase for the .key file got lost. So, when trying to execute ...
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5answers
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Confusion: Why isn't a passhrase encrypted SSH key two factor auth?

I'm trying to figure out the best practices for accessing my devbox from a public terminal. Most sources I've found recommend protecting the box with some kind of two factor authentication, such as ...
11
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8answers
269 views

How to choose a password that I have to remember for a long time but do not use a lot

I have a scenario where I have to remember a password / keyphrase, which I will not be able to recover if I forget it, for a long time (probably more than 10 years). The problem is because this ...
11
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2answers
2k views

Would an unnecessarily long password degrade performance of a WPA2 wireless network?

My friend wants to keep his home network super-secure, due to some trouble that he's had with unwelcome Wi-Fi intruders. So, naturally, he devised an ultra-long WPA2 passphrase (on the order of 100+ ...
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2answers
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How should I make diceware passphrases more memorable?

I find that truly random diceware passphrase, more often than not, either contain a word that is easily misspelled or has an order that is illogical. I think there are three ways to make a diceware ...
9
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2answers
2k views

How can a passphrase with 256 bits of entropy practically be constructed & memorized?

Quoting Wikipedia: A password with, say, 42 bits of strength calculated in this way would be as strong as a string of 42 bits chosen randomly[.] Assuming that interpretation is correct, combined ...
9
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4answers
632 views

Are there state-of-the-art techniques or theory specifically for attacking passphrases over passwords?

With passphrases becoming more and more common based on length being more important than complexity, I'm assuming there must be some work going on involving techniques aimed specifically at cracking / ...
8
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4answers
420 views

Will passphrases always be secure?

In a world where most people used passphrases instead of passwords, wouldn't an attack that generates a random string of words (alternating between word delimiters) be similarly effective to a brute ...
8
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1answer
181 views

Does eliminating the possibility of repeat words make Diceware passwords significantly less secure?

I read about Diceware passphrases and whipped up a little program to generate passwords in that style. I do this by taking the list of dictionary words to create passwords and "ordering them" by a ...
8
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1answer
65 views

GnuPG passphrase entry and X11 sniffing

Each time when I’m entering my passphrase in pinentry-gtk-2, every other X11 app may sniff it, as seen in $ xinput test-xi2 running in the background. What can be done about it? Or do I have to ...
7
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2answers
205 views

Realistically, how much added security does having a passphrase on a ssh key have?

Let's assume ssh key brute force is unrealistic. It seems to me your greatest vulnerability would be someone gaining access to a client filesystem. If that's the case then key loggers and a host of ...
7
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3answers
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SSL Certificate - is passphrase necessary and how does apache know it?

I want to generate a Certificate Signing Request for my server and in order to do so, I first need a secure private key. When I create a private key by using openssl genrsa -des3 -out server.key 2048, ...
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0answers
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Which format of secret would be the most efficient for human memory? [closed]

I am talking about something-you-know identification factor. Examples of those formats are passwords, passphrases, pin-s, picture passwords ( http://blogs.msdn.com/b/b8/archive/2011/12/16/signing-in-...
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3answers
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Is generating an RSA key with password and then stripping it off more secure than no password at all?

Some time ago I came across this question on SO; it asks how to remove the passphrase from an existing RSA key using a PHP equivalent to the existing openssl rss command. I've posted an answer with ...
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3answers
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What should I do if I type my password in the address bar, or type password in google search?

When someone accidentally types his or her password in one of the following three locations and presses enter, what should they do? username text box address bar Google search What do you suggest, ...
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3answers
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How secure is this method to remember security questions?

So I found an interesting method of remembering those pesky security questions. Basically, the guy takes a hash of the question (IE what is your mother's maiden name?) and then appends his own ...
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2answers
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Would a massive blacklist of guessable passwords be useful? [duplicate]

Suggestions to make a good password all focus on creating a string that a computer (or more likely, a network of computers with multiple GPUs) can not guess. Putting a password meter for when users ...
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4answers
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Passphrase - what is it exactly?

Well, according to Wikipedia, this is a passphrase; A passphrase is a sequence of words or other text used to control access to a computer system, program or data. A passphrase is similar to a ...
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2answers
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Expiration / enforce change of passphrase for private ssh keys

Out of curiosity, and also to check whether this is doable at all: Is there any way using standard tools to assign an expiry date [only] to the passphrase of an ssh private key, or to enforce the ...
4
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1answer
68 views

Why use a passphrase for RSA key?

Today I generated my first key pair, so my knowledge here is - so to speak - very limited. On client side I am using Windows and to log in I use PuTTY and I used PuTTYGen to create the keys. Here (...
4
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2answers
485 views

XKCD-like passphrases to stdout

I'm trying to find a way to crack XKCD-like passphrases (correcthorsebatterystaple) from word dictionaries. Basically concatenate X number of words from a dictionary file. Right now it honestly doesn'...
4
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2answers
988 views

LUKS, how to make strongest possible and reasonable passphrase?

Let us say I have a volume encrypted under LUKS with a 512-bit key. That would mean there are 2 ^ 512 possible values which the key may be. Now I need a passphrase which is at least as resistant to ...
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Computing entropy for a passphrase ( minimal word length … )

Edit: 2013-05-17 . 2013-05-27 After reading first answer from Tom Leek and some docs around the web, I've begin to write some options to my tool genpassphrase.pl: $ ./genpassphrase.pl -h Usage: ...
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1answer
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Change LUKS encryption key (not passphrase) without dataloss

You can change the LUKS passphrase without dataloss, but can you also change the actual key? I reckon you would have to re-encrypt the whole disk, but that would be acceptable to me. Background We ...
3
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2answers
222 views

With openssl des3, what are the passphrase parameters?

I'm using OpenSSL's des3 tool to encrypt a file, e.g. openssl des3 -salt -k SUPER_SECURE_PASSPHRASE < inputFile > outputFile Everything's working, but now I have to choose a final, fixed ...
3
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1answer
561 views

What is the entropy of just 1 Diceware passphrase like my passphrase?

A 5-word Diceware passphrase gives an entropy of 7776^5 = 3E19 = 19 Bans (or ~64 bits). Apparently monster cracking systems can currently guess passphrases for MD5 at a rate of 180 billion/sec (2E11). ...
3
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3answers
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How to use USB-Stick instead of passphrase?

I wanted to know if something exists that would allow the following. Whenever I use my RSA key(when using ssh for example) I'm prompted for my passphrase. I would like to, instead of being prompted ...
3
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1answer
33 views

Standard for Generating Multiple WEP Keys From a Passphrase

I've been reading a lot about WEP recently and why it was bad. To make sure I understand it, I've been writing scripts to show how it works and highlight its vulnerabilities. But I want to have a full ...
3
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1answer
47 views

Single randomly generated passphrase for both identity and authentication

There are questions about using a password only to identify and authenticate a user, rather than an email address or username plus password: Why do we authenticate by prompting a user to enter both ...
3
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1answer
2k views

find passphrase on encrypted ssh private key

I have an openssh encrypted private key. I don't remember the pass-phrase. I may be able to suggest words or patterns that may be in the phrase. I am looking for software that will help me recover ...
3
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2answers
391 views

Is a random keyfile more secure than a derived key?

I'm devising an encryption layer for some proprietary cloud storage API. Basically this should act as a transparent adapter that encrypts whole binary blobs (files) on upload and decrypts them on ...
3
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0answers
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Is there any merit to the RFC 3414 (SNMPv3 User Security Model) password-to-key method?

RFC 3414 (published 2002) specifies a method of generating keys based on password in its Appendix, which essentially takes any "passphrase", and keeps on repeating it until there is a 1MB string, at ...
2
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2answers
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Is it really “Time to add a word” if there are no tools to crack passphrases of 3 words and up?

It's "time to add a word" says Arnold Reinhold, the creator of Diceware, in his blog (3/2014). He advices to use 6 word sentences (or 5 words with one extra character chosen and placed at random) from ...
2
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5answers
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passphrases - lowercase and dictionary words

Amid all the discussion about password length vs. complexity (summarized by the famous xkcd strip and the followup dicussion) I am trying to make up my mind about passphrases made up with dictionnary ...
2
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1answer
30 views

What will happen if my GnuPG passphrase is discovered?

Hypothetically, should I be concerned if someone has my public key and knows my passphrase? Will they be able to decrypt messages sent to me?
2
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2answers
541 views

If I change my private key PGP passphrase, will the old private key+old passphrase work to decrypt already encrypted data?

Suppose I have a script that contains my PGP private key in plain text and requires me to manually type in the key passphrase to decrypt some data. Later, I decide that my passphrase is compromised ...
2
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1answer
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Strength of variable-length generated password

I am contributing to the Word Sequencer plugin for KeePass password manager, which can generate diceware-style passwords using a high-quality PRNG. Something in particular I'm working on is estimating ...
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1answer
323 views

How vulnerable are passphrases with grammatical structure?

Imagine I create a passphrase using random dictionary words but a common grammatical structure (eg: article, noun, verb, adjective, noun). Given a pretty small dictionary of 5000 words, how vulnerable ...
2
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0answers
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Passphrase generator and strength & recovery time estimator. Right strength and randomness?

Questions about the strength of pass phrases frequently popup, as does: how to generate a strong passphrase? I tried to combine both in a tool. The free tool also includes recovery time estimations ...
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1answer
398 views

What does the SSID have to do with a networks security concerning rainbow tables?

I have noticed in a few places people mention that if a popular SSID is used, it makes a network more vulnerable to rainbow table attacks. I saw this in one location and assumed they'd mistakenly used ...
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2answers
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Is it a good idea to combine words from different languages to increase a password's strength? [duplicate]

I was thinking of a way to generate a password that is easy to remember, but hard to crack, like the famous "correct horse battery staple" suggested by XKCD, also discussed here, and I've realized I'...