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 ...
45
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2answers
5k views

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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2answers
3k views

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
7k views

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 ...
18
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5answers
618 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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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 ...
14
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3answers
3k views

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 ...
13
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4answers
726 views

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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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
260 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
624 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
416 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
55 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
183 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 ...
6
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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, ...
6
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3answers
386 views

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 ...
6
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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 ( ...
5
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3answers
2k views

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, ...
5
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4answers
984 views

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 ...
5
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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 ...
5
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1answer
95 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 ...
5
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2answers
1k views

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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2answers
663 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 ...
4
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2answers
416 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 ...
3
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2answers
419 views

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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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 ...
3
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3answers
2k views

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
26 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
529 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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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
352 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 ...
2
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5answers
737 views

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
25 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
43 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 ...
2
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2answers
744 views

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 ...
2
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2answers
481 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
98 views

SSH key passphrase update and multiply locations

I have a ssh key which I use to upload code to github. the private key is located on several locations from where I upload/download data. I wonder how can I update (or expire) old keys after I update ...
2
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1answer
301 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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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 ...
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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
294 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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1answer
313 views

Does AES 256 encryption support a master key and generated (time-bombed) keys?

I have a scenario where semi-sensitive [1] data for a corporate web application is to be stored in the browser's localized storage (Indexed DB to be specific, via JavaScript). The intention is to ...
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1answer
92 views

why are passphrases not the standard

I have seen many questions concerning passwords: how to measure password strength, why don't we pick passwords for the users and obviously the best one: passwords vs phrases and the one i would like ...
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1answer
385 views

Can you recover the password from ZipCrypto encrypted ZIP file?

I know that "legacy ZIP-crypto" is not secure and you can get at the contents of the file quite easily. Now the question is, can you also get at the password (assume this is a very long, very high ...
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3answers
184 views

cleartext passphrase for keystore

How is passphrase for a keystore to be stored? we have all passwords encrypted and the key to encrypt is stored in keystore , so how is the passphrase for the keystore to be stored? in clear text? if ...
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1answer
56 views

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
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How to detect whether a GnuPG private key has passphrase on it from a script?

I've written a script to help our developers store a copy of their private keys without a passphrase inside our Puppet tree (not committed to Git) so our Vagrant boxes can use Hiera with eyaml + gpg ...