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

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Security of bcrypt/sha256 key used with AES to encrypt a file

I'm looking to encrypt files using secure hashing and encryption algorithms in Python. Having used bcrypt in the past, I decided to use it for my passphrase calculator, then pass the output through ...
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3answers
584 views

Password strength metrics

In the question Source code as password I suggested using a combination of entropy and as @Lawtonfogle put it 'meatspace difficulty'. As suggested in the xkcd comic correct staple horse battery is a ...
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2answers
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Is it a good idea to store Email addresses as hash only?

I am currently building a web service at http://write-math.com similar to http://detexify.kirelabs.org/ that should help users to get LaTeX code from drawn formulae. It is part of my bachelors thesis ...
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3answers
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What are the security implications of using TOTP for single factor authentication?

(Note: I am not actually planning to do this. This question is strictly theoretical.) TOTP is commonly used as the second factor in Two Factor Authentication. It is an open standard with available ...
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2answers
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Storing third-party auth info securely

Suppose there's a multi-user web application that requires access to user's mailbox (on third-party service, like gmail, etc.). This access needs to be persistent. Which means we'd have to store user ...
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4answers
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Does Windows have a built-in password store?

What passwords are stored in Microsoft Windows? How can I know what password are saved in computer?
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7answers
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Is it possible to detect password length from hash? Does doubling your password add more security?

Assuming a service doesn't store a plain text password, am I right in saying that the answer to this question depends on the service? On a bad service, the hash length is related to the password ...
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2answers
264 views

Is there a site like plaintextoffenders.com that shames companies that force insecure passwords?

I recently came across http://plaintextoffenders.com/ and I liked the idea. I wondered if there was a similar site that shames websites that force insecure passwords? I personally have a list of a ...
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4answers
531 views

Is it secure to use similar password over different accounts?

I have a strong password which is a long, unfamiliar word phrase. I would like make other account use a password with similar level of complexity but I don't like to remember so many password over ...
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3answers
718 views

Cracking passwords after a pattern with John

So I am trying to find out how easy it is to crack a password using some great Linux tools. We all know about John as a password cracker and how great it is. But how about specifying a pattern. ...
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4answers
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Is it bad practice to use the same password on different sites?

Is it considered bad practice to use the same password on separate sites, if so why? Even if the passwords to a site are compromised the attacker still doesn't know the user names or sites the same ...
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16answers
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Is the BBC’s advice on choosing a password sensible?

In this article on the BBC’s website they offer advice on how to develop a password. The steps are as follows. Step 1: Choose an artist (a recording artist I presume) Lets choose as an example ...
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11answers
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Technology that can survive a “Rubber-Hose attack”

In the documentary film Citizenfour, Edward Snowden says about documents: I'm comfortable in my technical ability to protect [documents]. I mean you could literally shoot me or torture me and ...
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10answers
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New Gmail login system—going against conventional wisdom?

I noticed that the new gmail login asks for username first, and then confirms if such username exists, before asking for password input. Does this not go against conventional security wisdom to not ...
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14answers
7k views

How to store passwords written on a physical notebook?

Answers to the question "How safe are password managers like LastPass?" suggest that storing personal passwords on a physical notebook might be a reasonable option: I know someone who won't use ...
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7answers
11k views

Why isn't open WiFi encrypted?

As far as I understand, WiFi networks that require no password send traffic through the air unencrypted. Those that require a password encrypt each connection uniquely, even if they're all using the ...
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3answers
4k views

Security Review - password_hash implementation for PHP

I'm currently working on a "helper function" for PHP's core to make password hashing more secure and easier for the majority of developers. Basically, the goal is to make it so easy, that it's harder ...
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8answers
9k views

Convincing my manager to use salts

My manager says we don't need to salt our passwords because people are not likely to use the same password because they all have different native languages, in addition to the websites they are active ...
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4answers
15k views

Is using SHA-512 for storing passwords tolerable?

I know that the best options to use for storing passwords are bcrypt/PBKDF2/scrypt. However, suppose you have to audit a system and it uses SHA-512 with salt. Is that "fine"? Or it is a vulnerability ...
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6answers
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Modern high quality password dictionary

Has anyone come across any good password dictionary lately? Some of the lists I found dated back to 90's! Some are simply too big that I doubt their quality. There appears to be some work by someone ...
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11answers
43k views

Are password-protected ZIP files secure?

Following my answer. If I can list contents of a password-protected ZIP file, check the file types of each stored file and even replace it with another one, without actually knowing the password, then ...
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10answers
12k views

Why does the user pick the password?

Almost every web service I can imagine has the user pick the password. Why is this? Couldn't the system choose a better password? It doesn't have to be some complicated mess; see ...
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10answers
6k views

Password Management within an Organisation

Within an organisation there are many passwords such as those for root accounts on servers, hosting accounts, router logins and other such things, that need to be kept track of. I know in some ...
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2answers
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Why are GPUs so good at cracking passwords?

What is it about GPUs that lets them crack passwords so quickly? It seems like the driving force behind adopting good key-derivation functions for passwords (bcrpyt, PBKDF2, scrypt) instead of ...
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7answers
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“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" ...
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10answers
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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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11answers
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Is there any way my password is hashed, if I'm only ever asked to provide 5 out of many characters? [duplicate]

There is a system that, on a login form, presents about 40 boxes for password letters (to hide password's actual length), and only random ones (the same amount each time) are editable. Explanation is ...
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5answers
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How can I know that developers will be ethical and not record my password in plaintext

I am not asking why hashing should be done. Instead, I want to know how to prevent that developers record user passwords to hack their user's other accounts, especially their email. Couldn't they ...
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7answers
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What is a good way to authenticate a user to a smart phone?

What would be a good way to authenticate a user to a smart phone? By good, I mean that it is both secure, and user-friendly. Passwords don't seem to be the best fit because a password needs to be ...
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4answers
7k 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 ...
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4answers
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Is it safe to store a password hash history for preventing user to keep same password repeatedly in some cases?

I am developing an application in PHP and it uses bcrypt encryption to store passwords. I want to keep the history of hashes whenever the user changes the password. By doing this I want to stop the ...
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1answer
9k views

Why use an authentication token instead of the username/password per request?

The author of http://stackoverflow.com/a/477578/14731 recommends: DO NOT STORE THE PERSISTENT LOGIN COOKIE (TOKEN) IN YOUR DATABASE, ONLY A HASH OF IT! [...] use strong salted hashing (bcrypt / ...
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4answers
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HTTP Basic auth password storage more secure than Digest auth

If you are using SSL already, it appears Basic auth is the way to go since you can perform bcrypt with the password when you store it in the database, where as Digest auth only allows md5. As we know, ...
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6answers
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Is AES encrypting a password with itself more secure than SHA1?

This isn't really a practical question, but more a question of curiosity. I heard a CS professor recommend stepping up from md5ing passwords not to SHA1, but to AES encrypting the password using ...
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3answers
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MD5 collision attacks: are they relevant in password hashing?

DISCLAIMER: This is not an endorsement of MD5 as a password hashing function. I know about parallelization, GPUs, and dedicated password hashing functions like bcrypt and scrypt. With that out of ...
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1answer
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Facebook password lowercase and uppercase

Recently I logged into my Facebook account and then noticed that my caps lock was on. So I tried to log in again with and without capslock on. I got in both times. Then I tried to log in with the ...
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3answers
811 views

How to manage team passwords?

How do most teams handle the storage of passwords, in particular the required changes when team members leave ? Right now, we use a centrally stored encrypted file but the thought of changing 100's ...
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4answers
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If email is insecure, why do we use it for password resets?

I found myself telling a coworker today "Email is insecure, that's why we developed our secure report application." But then it struck me, Why is email considered insecure? If it is so insecure, why ...
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6answers
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Does verifying identity by positions in passwords mean passwords are stored unhashed? [duplicate]

If authentication occurs by asking the user for the characters at certain positions in the password (such as: give the 3rd and 7th character in the password), does this imply that passwords are stored ...
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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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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 ...
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3answers
587 views

Is it inconsistent to tell users to “not click on password links in email”, and requiring clicks on “forgot password” links?

On one hand, IT Security shops have been telling users to not click on links in email because they can do damage to your computer, or phish your personal information. Many of those issues are ...
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5answers
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 ...
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11answers
5k views

Definitely safest password storage scheme?

I already asked this on StackOverflow but I was suggested this would be a better suited place and I found no way to "move" the question so I have to copy it. Believe, I know, there are hundreds ...
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4answers
2k views

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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4answers
8k views

How secure is Windows 8's Picture Password login?

The final Windows 8 build has been released to manufacturing. One of the new features of Windows 8 is "Picture Password", where the end user logs on to Windows by clicking a specific pattern on the ...
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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
2k views

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 ...
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1answer
700 views

Perfectly Robust Hashing Scheme, or Completely Over-Engineered?

This is going to get long, so prepare. Basis of the question is, Do all these steps improve security, or am I completely overthinking the problem? Are my assumptions/thought process valid? We all ...
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1answer
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What's the risk if I accidently type my password into a username field (Windows logon)?

I'm used to logging into my personal Mac which is a password-only field (like waking from sleep mode). Sometimes I have to use a Windows network on which I have an account, but of course I have to ...