Specific to the security of passwords: hashing, entropy, cracking, resets, lockouts, etc.

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29
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2answers
8k views

I just send username and password over https. Is this ok?

When a user's logging in to my site, they send their username and password to me over https. Besides the ssl, there's no special obfuscation of the password - it lives in memory in the browser in the ...
2
votes
2answers
297 views

Company sending Master passwords in unencrypted emails

If a company has terrible security policies like letting people email password in cleartext emails, what to do if they reject all fair minded advice?
18
votes
2answers
2k views

Sending temp password when users first registered - is that good for anything?

One of our clients has sent us a list of security requirements. One of them was that registration does not including setting a password - once complete, a temp password is sent to the user, and the ...
6
votes
2answers
840 views

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 ...
18
votes
3answers
6k views

Deleting a Java Object securely

I know that in order to delete a Java object I should use character array instead of String, since I can safely erase (rewrite the character array with other data) its content. This seems not to be ...
3
votes
2answers
549 views

Can a survey website viewed in Firefox trick the user into sending stored passwords?

Firefox stores passwords (I am not referring to the Master Password feature) and I would like to know if a survey website can steal those passwords. I was typing a URL and perhaps I mistyped it and ...
1
vote
1answer
93 views

What function(s) to be used to generate Salt on Windows Mobile 6

I am looking for THE or a real function I can use to generate salt for my mobile app on Windows Mobile. In case I am not abusing in this request but in the future I plan as well the same app for ...
22
votes
4answers
3k views

How would you store a 4 digit pin code securely in the database?

I'm familiar with password hashing, using salts, bcrypt etc. But it doesn't seem like this would work to store a 4 digit pin code since the attacker could try all 10,000 combinations quite quickly. ...
4
votes
1answer
479 views

How can I manage multiple sets of passwords accessible by different users? [duplicate]

Possible Duplicate: Sharing passwords and credentials between founders and employees I use KeePass for my personal passwords. I would want to use it for my business, too, but the only way ...
6
votes
3answers
857 views

Attack vectors for brute-forcing website passwords

When talking about password security, a lot of discussion centers on the risk of a password being guessed in a brute-force attack. For websites where a user has registered an account, what are the ...
4
votes
4answers
1k views

Brute-force heuristics used in password cracking

Existing questions on this site discuss some of the heuristics used by password cracking tools to avoid doing a completely naive brute-force search (for example, "dictionary word with number ...
6
votes
4answers
2k views

Password entropy in layman's terms

Entropy is a term used often in relation to password security and brute-force attacks, but it is a topic that can get complicated quickly. What is the best way to describe password entropy (what it is ...
8
votes
4answers
2k views

Passwords - any statistics on user behavior?

I'm looking for analyses of how users choose and use passwords. I'm sure there are many resources out there that analyze user passwords. For instance, I've seen many people analyze dumps of password ...
7
votes
5answers
385 views

Is there any added security benefit to username complexity requirements?

I've come across several sites lately that have complexity requirements for usernames like "must be 8 characters long and contain at least 2 numbers". Is there any real added benefit to this from a ...
38
votes
2answers
4k 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 ...
9
votes
3answers
8k views

Security of passwords remembered by Windows

Does Windows XP or Windows 7 encrypt saved passwords? I'm assuming that the user uses local password to logon. The user then uses his own computer to connect to server in work and sets the "remember ...
22
votes
10answers
4k views

Best password strength checker

In XKCD #936: Short complex password, or long dictionary passphrase? Jeff claimed that password cracking with "dictionary words separated by spaces", or "a complete sentence with punctuation", or ...
12
votes
5answers
771 views

Should passwords be truly random?

When generating a password, should it be "truly random" or should I make it a little less random by enforcing some rules? If a password is generated at random, it could come out all-lowercase letters ...
34
votes
8answers
2k views

Who is responsible for the strength of user's passwords?

Who is responsible for a user's password's strength? Is it us (developers, architects, etc.) or the user? As a web developer, I've frequently wondered whether I should enforce the minimal password ...
21
votes
12answers
3k views

Why do we even use passwords / passphrases next to biometrics?

In the last couple of days there were a lot of talking about passwords and passphrases, not only here, but on several blogs and forums I follow (especially after XKCD #936 saw the light of this ...
9
votes
4answers
543 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 / ...
17
votes
3answers
3k views

Should I have a maximum password length?

I'm creating a webapp, and part of my authentication method is password length. Should I put one in place? (say, 50 characters?) Or should I just put a minimum length (Currently at 6). Are there ...
59
votes
21answers
13k views

How can I avoid my password being harvested by key loggers from internet cafes?

During traveling, especially in poor countries, sometimes you are going to need to use the internet at an internet cafe and you really can't be sure whether anyone has installed anything to listen to ...
14
votes
2answers
1k views

Are there some good papers (or discussions) on using Markov chains or Hidden Markov Models for password auditing/cracking?

As a programmer and language enthusiast I've been very interested in Markov chains for some time. Considering the influence of natural language on password and passphrase selection (by humans of ...
11
votes
2answers
1k views

Password auditing

Most password policies require the password to be at least 8 characters long and contain symbols from at least 3 classes (lower case letters, upper case letters, numbers, other). Problem is, that a ...
14
votes
2answers
2k views

Tamper-proof BIOS password & settings storage with Trusted Platform Module?

In the olden days, one could trivially bypass BIOS passwords on most PCs by removing the BIOS battery and clearing the CMOS. My question is: On modern PCs equipped with a Trusted Platform Module ...
6
votes
4answers
2k views

Are there lists of most common words or ngrams used in passwords and passphrases?

I've been thinking about ways to focus brute forcing dictionary attacks on passwords and passphrases based on the assumption that certain words, combinations of letters, and combinations of words are ...
6
votes
3answers
310 views

Are there password/passphrase guessers/crackers which can utilize facts supplied about the target?

I was just reading a discussion about cracking passwords that said the person running the tool might know things about the target like the birthday of his first girlfriend's dog but the tool won't. ...
6
votes
4answers
5k views

Are the iPhone “connect the dots” passwords secure?

A popular way to login to iPhones and other phones is to use a "connect the dots" password. For those unfamiliar, it looks something like this: Is this kind of passwords secure from brute force ...
5
votes
5answers
2k views

What password cracking software is commonly used?

I am curious to know how secure my passwords are. What password cracking software is commonly used? Preferably open source. EDIT: I am actually looking to crack my passwords used on services I ...
21
votes
5answers
3k views

How can I choose a strong password that is easy use on a smartphone?

Typing on a smartphone is tedious. Special characters are the hardest; lowercase letters are generally the easiest. But even a long all-letter passphrase like "correct horse battery staple" is ...
632
votes
21answers
127k views

XKCD #936: Short complex password, or long dictionary passphrase?

How accurate is this XKCD comic from August 10, 2011? I've always been an advocate of long rather than complex passwords, but most security people (at least the ones that I've talked to) are ...
14
votes
4answers
10k views

Is it possible to securely store passwords using reversible encryption?

Everyone says that you need to use a non-reversible hash when you store passwords so that even if your database is leaked, the passwords themselves are still safe. I'm wondering if there is anyway to ...
38
votes
7answers
3k views

“Real” Salt and “Fake” Salt

During a Q&A period at DEFCON this year, one member of the audience mentioned that we're using "fake salt" when concatenating a random value and a password before hashing. He defined "real salt" ...
7
votes
2answers
3k views

Dictionary Attack on Wifi

I know a few people with pretty weak passwords. What kind of systems exist to prevent dictionary attacks? Would it make sense to restrict the number of connection attempts in a certain timeframe? ...
7
votes
7answers
1k views

Facebook account keeps getting hacked, can't seem to figure out why or how?

One of my mate, she has a lot of friends on Facebook, uses it for marketing. Her account keeps getting broken into. Her password gets reset and/or gets locked for changing resetting password too many ...
7
votes
4answers
2k views

Web browser password management security [duplicate]

Possible Duplicate: How are browser saved passwords vulnerable? How secure are the password managers that are built into modern web browsers? Currently I use lastpass plugin as I believed ...
11
votes
2answers
1k views

Can a Firefox add-on or plug-in access the user's websites' saved passwords in decrypted mode?

Going deeper into the previous question on Firefox plugins and add-ons malware risks: Could a Firefox add-on potentially decode and capture the encrypted websites' passwords saved in the browser?
18
votes
5answers
898 views

Is there any legal reason to save a cleartext password?

I called customer service of a well known company and discovered that the operator had the ability to view my website password in clear text on her screen. I asked her about this and she defended the ...
7
votes
8answers
872 views

Is the following authentication scheme secure?

I was trying to design an authentication system that would make it much harder to guess a password via brute force, and reduce the risk to a user if the hashed password was stolen through a snooping ...
5
votes
2answers
337 views

Is cascading cryptographic algorithm better than using a single one?

Am I wrong to think that scrypt(bcrypt(password)) would be better than using sole (s|b)crypt? Especially when considering two different key for the two algorithms. I am also interested in some ...
35
votes
3answers
2k views

Am I wrong to believe that passwords should never be recoverable (one way hash)?

I recently forgot my password for our cable provider online account, only to discover that they sent it to us via plain text in an email. I quickly sent an email to customer support asking them if ...
7
votes
2answers
4k views

Why limit passwords to ascii printable characters? [duplicate]

Possible Duplicate: Do non-keyboard characters make my password less susceptible to brute forcing? Every article on password security that I read tells people to make the password more ...
4
votes
2answers
7k views

What password-based encryption to use with standard Java 6?

Which password-based encryption method should I use in Java 6? It should be as strong as possible, but work with the default security policy file (not the export restricted one which you have to ...
32
votes
1answer
5k views

Are there more modern password hashing methods than bcrypt and scrypt?

This question made me start thinking about password hashing again. I currently use bcrypt (specifically py-bcrypt). I've heard a lot about PBKDF2, and scrypt. What I'm wondering is if there are any ...
35
votes
15answers
6k views

Why do people think that this is bad way to hash passwords?

Well, please tell me, what's wrong with this code: $password = "hello"; $password = md5($password); for($i=1;$i<20;$i++){ $password = md5($password); } It's exactly the same as this one: ...
0
votes
2answers
797 views

Best ways to store a password Server side [closed]

I was using Lotus Notes today and I realized that the program asks password is encrypted in many ways. even without access to the stored passwords notes I can say that they are at least as recorded in ...
50
votes
8answers
4k views

Is it OK to tell your password to your company's sysadmin?

I'm working in a small company (20 employees) as a senior software engineer. After having problems with my email, our newly employed IT administrator asked me to write my user password to someone in ...
15
votes
3answers
546 views

Is it OK to tell your password to an admin? [duplicate]

Possible Duplicate: From a security point : Is it OK to tell your password to an admin? I am working in a small company (20 employees) as a senior SW engineer. After having some email ...
15
votes
6answers
3k views

Managing website passwords for small team

I'm part of a small group of people who manage a website and the server it runs on. We have many accounts with third-party websites or services that multiple people on the team need to access. What is ...