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

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9
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4answers
552 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 ...
60
votes
21answers
14k 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
3k 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
315 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 ...
660
votes
21answers
133k 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 ...
40
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
2k 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
922 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
905 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 ...
9
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
814 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 ...
51
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
566 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 ...
16
votes
6answers
4k 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 ...
14
votes
2answers
3k views

What are the most common password salting methods?

I learned that the Sun guys used the login name as salt for password hashing. Is this a common approach? What are the most common salt values?
21
votes
3answers
5k views

Security of LastPass + YubiKey

I'm looking at password manager solutions and came across LastPass. I see they also support two-factor authentication using YubiKeys. How secure is this combination for password management? What are ...
7
votes
2answers
789 views

Encryption Algorithms with an error code for wrong password

I am looking for an encryption algorithm that would allow me to know if the password supplied is the correct one or not. This question can be considered as a follow-up for Q. In particular the answer ...
5
votes
2answers
13k views

Where/How is an ODBC password stored when 'saved' in Access?

I have been working on a program that uses MS Access and ODBC to connect to an SQL server. One of the requirements is that the user need not know the password for the connection to the SQL server, so ...
11
votes
5answers
647 views

Security of using passwords or even passphrases to encrypt files

Is it ever appropriate to use real-world passwords to encrypt files to be sent via unsecure means. By real world, I mean a password that is memorable and memorisable by a mere person? I am implying ...
6
votes
2answers
861 views

Is it better to hash n*x times in sha1 or n times in sha512 on the client side?

I already know I"m going to hash the user's password n times in either sha512 or n*x in sha1 before it is sent to the server. Once at the server, I'm going to use bcrypt set to use ~1/100th of a ...
4
votes
2answers
6k views

Can DES-based hashed password be recovered if salt is known?

Can a hashed password be recovered if the hashing is done with DES based crypt function in PHP and both the hash and salt are known by the attacker? Consider the following example: $salt = 'mysalt'; ...
14
votes
2answers
998 views

Salting password with the first 8 bit of the password itself

Do you guys think salting password with the first 8 bit of the password itself will have same result as using stored salt to hash password? [Clarification] I am not storing salt but creating from the ...
12
votes
2answers
1k views

Is there any advantage of bcrypt over multiple iterations of SHA-x/MD5?

I know that a good password hashing algorithm should be slow. MD5, SHA256, etc. are fast. So I've been adding multiple iterations of SHA-256 hashing to my web apps (around 50000). Getting the hash of ...
2
votes
4answers
3k views

LDAP vs MySQL for Usernames and Passwords

I understand the LDAP databases are more secure, but is it always necessary to use LDAP instead of MySQL for usernames and passwords?
25
votes
4answers
6k views

Security of passphrase-protected private key

If an attacker obtains a private key that was created with no passphrase, he obviously gains access to everything protected with that key. How secure are private keys set up with a passphrase? If an ...
8
votes
4answers
2k views

How to protect ftp account information in the source code of a program

I wrote a game which stores high score information on an ftp server. In the the source code I need to write out the ftp link with the account name and password in it. For example: url = new ...
4
votes
3answers
444 views

Hashed passwords - How many variations of rainbow tables?

First off...I passed the CISSP exam. WOOOO. I had to get that out. GCIH and CEH by Sept. 11' So, while studying for the technical side of things, I see that there are rainbow tables. They are ...
19
votes
4answers
1k views

Is it a bad idea for an information holder to e-mail a user their password?

A couple of websites with which I'm registered have, after a period of inactivity on my part, each sent me an e-mail to remind me that I'm still registered. In each case, that e-mail has included my ...
-1
votes
1answer
3k views

How can I avoid sending passwords in plain text when logging into a website?

Suppose that I login to a website. When I type my personal data, aka, password and email, the password is sent in clear text to the server, correct? Then, a network card in promiscuous mode can ...
3
votes
1answer
1k views

Will using unicode chars in my password increase security? [duplicate]

Possible Duplicate: Do non-keyboard characters make my password less susceptible to brute forcing? Bruteforce tries cracking the hash with every possible combination of letters. Then, If ...
19
votes
4answers
2k views

What to transfer? Password or its hash?

Let's say in my database I store passwords hashed with salt with a fairly expensive hash (scrypt, 1000 rounds of SHA2, whatever). Upon login, what should I transfer over the network and why? Password ...
46
votes
6answers
6k views

How do some sites (e.g. online banks) only ask for specific characters from a password without storing it as plaintext?

I thought How can a system enforce a minimum number of changed characters... would answer my question, but it seems this is a different case. When I sign on to my online banking account, I'm prompted ...
26
votes
6answers
26k views

Most secure password hash algorithm(s)?

What is/are currently the most cryptographically secure hashing algorithm(s)? (available in PHP) Speed is irrelevant, because I'm iterating the hash over a fixed time (rather than a fixed number of ...
346
votes
21answers
65k views

How does changing your password every 90 days increase security?

Where I work I'm forced to change my password every 90 days. This security measure has been in place in many organizations for as long as I can remember. Is there a specific security vulnerability ...