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

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Are password complexity rules counterproductive?

In creating a login for this site I chose a nondictionary password that would be extremely hard to guess, but easy to remember. I was told that it did not meet complexity rules. After several ...
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5answers
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The AES Crypt implementation hashes a password 8192 times to generate the key. Is this necessary?

I'm considering encrypting some small files (hundreds of kb apiece) using the AES Crypt reference implementation. Looking at the source, it seems that the encryption key is derived from the IV and the ...
16
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3answers
1k views

Storing passwords in reversible form - a genuine use-case

What's wrong with you, you crazy fool, you're not supposed to be able to retrieve a password in plain text! I know. Hear me out. Assume I've got a service that's similar to Mint.com. For those that ...
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7answers
2k views

How different should my passwords be? [duplicate]

Suppose I use remember one long high entropy master password, and use variations of it for each of my passwords. Eg if I remember tSaF4nWeACVkUU4 as a master password and use tSaF4nWeACVkUU4t (with a ...
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4answers
12k 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 ...
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4answers
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Does two-factor authentication reduce the need for a long password?

I've recently enabled 2-factor auth on a number of web apps, mostly using Google Authenticator. Does this mean that the importance of a strong password on each site is reduced? I would prefer to use ...
16
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4answers
358 views

Are malicious relying parties able to abuse OpenID logins?

if I logon with OpenID into a website (crafted by attackers/hackers) I want to know how much damage can they do to me? Are they able to steal my contact info, name, etc (assuming I'm using Gmail ...
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2answers
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What's wrong with storing private keys in the cloud?

I know this sounds like a dumb question, but whats wrong with it? Assuming that all private data is encrypted (by the client) using PBE AES256, then is this scheme more vulerable than storing keys on ...
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4answers
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Should I be worried if I accidentally entered my password in a username field?

Occasionally I will fail to hit Tab properly when entering a username/password combination. This results in me submitting username "myUsername$ecretPa$$word" along with a blank password. I always ...
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2answers
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How secure is Keychain on OS X?

Keychain is a built-in app on OS X that stores all of the user credentials, and allows for one to keep encrypted notes in an easily accessible way. Does anyone know how secure Keychain is? I know ...
15
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7answers
833 views

To salt, or not to salt? [duplicate]

Possible Duplicate: Why is using salt more secure? Why would salt not have prevented LinkedIn passwords from getting cracked? Recently I decided that I wanted to learn more about web ...
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11answers
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Should I know my users passwords so I can check they can logon? [duplicate]

I have an issue with support for a system and I don't know what approach to take. It boils down to the question: Should I know my users passwords so that I can check with certainty that a ...
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3answers
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Is it a bad idea to add random characters to user ID and password?

I've heard people say again and again that you shouldn't implement your own security algorithm, and I'd like to ask you if I'm breaking this rule. I'm creating a traditional client-server application ...
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5answers
1k views

Is it legal to log passwords from failed logins?

Is it legal to store/log mistyped passwords? How many of you have seen this happen in a log file or DB?
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5answers
64k views

How to generate dictionary for a dictionary attack?

I need to crack my own password. Advantage is that I know possible characters and maximum length. What I need is to create a dictionary. The dictionary should contain all the combos of characters ...
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2answers
5k views

How Does A Random Salt Work? [duplicate]

I don't understand how using a random salt for hashing passwords can work. Perhaps random salt refers to something other than hashing passwords? Here is my thought process: The salt is used to add ...
15
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11answers
5k views

Best practice for password distribution

I am about to set up a new account on my Linux server for a user that lives in another state in the U.S. I can't think of a good way to get them this user their password. There must be a standard ...
15
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7answers
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Password management/synchronization?

Is there a good enough service I could run on my own home (Linux) server that I could use for storing/accessing/synchronizing passwords so they could be available for me from multiple ...
15
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7answers
357 views

Is a “security measure” that doesn't provide a security benefit actually harmful?

If a security measure is implemented that doesn't provide any additional security benefit, can it be considered harmful? As an example, consider a login page where the user is asked to enter their ...
15
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6answers
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Do salts have to be random, or just unique and unknown?

First of all, my motive is to avoid storing the salt in the database as plain text. As far as this question is concerned, the salt is not stored in the database. After discussion in comments and in ...
15
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3answers
7k views

Is a HMAC-ed password is more secure than a bcrypt-ed or scrypt-ed password?

Given an option , which one should I choose , a HMAC for storing a password securely or a bcrypt or scrypt library?
15
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6answers
39k views

Recommend Length for Wi-FI PSK?

I currently have a network set up with WPA2 and AES encryption, the password is 8 characters long but was randomly generated and contains no dictionary words. However I'm concerned about the ...
15
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2answers
1k views

How does varying character type increase strength of password?

When creating a new password, people often recommend you use both uppercase and lowercase characters, numbers, and symbols. How does adding any of these increase the strength of a password? There ...
15
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2answers
960 views

Distance between two passwords

It is known that people reuse their passwords across different sites. The reuse can be done in two ways: using exactly same password for two different sites, slight modifying the password of one ...
15
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1answer
899 views

Linux /etc/shadow password change security

I wonder what happens what happens when I am changing my password on a Linux system. Basically all passwords are stored in a file called /etc/shadow or /etc/master.passwd in BSD-like systems as I do ...
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3answers
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Cracking MS-CACHE v2 hashes using GPU

As most people here will know, Windows caches domain/AD credentials in a format known as MS-Cache v2. Obviously, these would be excellent passwords to gain during a penetration test when local access ...
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4answers
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How are browser saved passwords vulnerable?

Most browsers offer to save the password after entering it on many logon pages. What types of vulnerabilities are there for such saved passwords. I'm interested in what ways malware on web pages ...
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2answers
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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 ...
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2answers
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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 ...
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2answers
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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 ...
14
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6answers
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Is this login security enough?

I'm coming up with my next login system for admins of an e-commerce website, which will have this: login form is SSL secured password is converted to SHA-256 before being transmitted (bcrypt is too ...
14
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4answers
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Is an 80 bit password good enough for all practical purposes?

I know that asking how many bits of entropy comprise a strong password is rather like asking the length of a piece of string. But assuming the NSA is not on to you, and that it is hardly worthwhile ...
14
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2answers
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Linux password changed. Is this an attack or a hardware glitch?

My Linux (Ubuntu 12.04) password suddenly changed last night and I'm not sure if this is an attack or just a hardware/user error. This is on a personal/non-server box. Several strange events led up to ...
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5answers
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What are the differences between an encryption seed and salt?

Today I had a hard time explaining the difference to a friend. I know seeds are used when generating "random" strings. And salts are used when providing different outcomes to a hash. What is a ...
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2answers
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Password and Generated number - How does it work?

In my company, they don't allow accessing the company email or servers from outside the company network. To access the email from outside the network, you have to use: Username, password and a number ...
14
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4answers
955 views

If a website allows another person to get a list of the site's users passwords, how likely is it that the passwords are stored in cleartext?

We had an incident where some of our managers were given passwords for the people they supervise using a particular company website. Ostensibly it was done so the managers could check in on the users ...
14
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4answers
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Looking for example of well-known app using unsalted hashes

Does anyone know of a well-known application that still uses unsalted hashes for password storage? I'm looking for an example for an upcoming lecture on Rainbow Tables, and I think it would add ...
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8answers
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Are services like “LastPass” less secure, as they have all my passwords protected by a single password?

If the LastPass service has all my passwords and someone gets access to my LastPass password, this person will have access to all my passwords. Isn't that bad for security?
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3answers
898 views

What can I do if my bank thinks my date of birth is “known only to me”?

My bank has recently replaced passwords with occasionally asking me information that is "known only to me". Such information includes my date of birth, postcode, and my mother’s maiden name. ...
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5answers
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How can I avoid putting the database password in a perl script?

I have a cronned perl script that connects to our database and does various kinds of lookups and integrity checks. The original script was written by someone long ago. My job is to make some changes ...
14
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6answers
857 views

Is there additional security value in using passwords with words or phrases in non-English languages?

I was thinking about correct horse battery staple. I am not a native English speaker. In my language, the above could be written as: vqrno kon bateriq telbod OR вярно кон батерия телбод. Keep in ...
14
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6answers
663 views

Primary Key as Salt?

Is it okay to use the primary key as the salt in a Users table? The only disadvantage that I can see is if the PK changes (unlikely), then the passwords break. What are your thoughts?
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2answers
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How many passwords does the average user know?

Looking for research on the count and complexity of passwords that an average user is actively using. Note: Also, just to be clear, by research, this is not a request for you to respond with an ...
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2answers
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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?
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6answers
964 views

Is there any security risk in storing hashed variations of passwords?

For example, if hypothetically an application requirement was to tell users when their password might have failed because caps-lock was turned on, and hypothetically there was no way for the ...
14
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2answers
7k views

With PBKDF2, what is an optimal Hash size in bytes? What about the size of the salt?

When creating a hash with PBKDF2, it allows the developer to choose the size of the hash. Is longer always better? Also, what about the size of the random salt? Should that be the same size as the ...
14
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1answer
868 views

XKCD #936: under what assumptions is 1000 guesses/second over a network plausible?

In XKCD #936, a rate of 1000 password guesses/second is proposed as a "plausible attack on a weak remote web service". Under what assumptions is this rate plausible? It seems much too high to me. I ...
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3answers
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Should security question answers be case-sensitive?

Question In the case of security questions being used to reset an account password, what is considered best practice for handling case-sensitivity on the security question answers? Scenario An ...
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2answers
536 views

Concrete figures on password cracking in the wild

While password guessing is a science, not every attacker out there is up-to-date with the latest advances or cares to invest in GPUs or FPGAs. It's easy enough to test online password guessing ...
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5answers
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Why should I have secure passwords for sites that I pay bills on?

What's the worst that can happen, the hackers will pay my bills for me? Assume that this isn't a malicious hacker out to disconnect my electricity. What kind of concerns are there for my finances, ...