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

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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 ...
14
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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
2k views

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 ...
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2answers
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Does it make sense to choose a longer password than the output of a hash?

Let's take MD5 for example: It outputs a 128-bit hash. Does it make sense (in theory) to choose an input (password) which is itself longer than 128-bit? Does it increase the probability of a ...
14
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4answers
967 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 ...
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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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5answers
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Can sites which check your password as you type pose a security risk?

Some sites that I use check my password as I type it into the login (not registration) form. So, for example, to begin with I might have: Username: sapi ✓ Password: passw × and by the time I've ...
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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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1answer
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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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6answers
900 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
679 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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3answers
9k views

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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6answers
1k 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 ...
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3answers
4k views

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
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Bypassing the BIOS password

Are there any reliable methods that allow an attacker to bypass a BIOS password, or alter BIOS settings without entering the password? A few ideas come to mind: The old battery trick (remove ...
14
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3answers
22k views

Is a password protected PDF file safe for bank statement attachments?

My bank emails my monthly statement to me in a password protected PDF attachment. Is this a secure method of transmitting something as sensitive as bank statement?
14
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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?
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2answers
541 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 ...
13
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5answers
2k views

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, ...
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6answers
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Is PBKDF2-based System.Cryptology.RFC2898DeriveBytes() “better” for Unicode Password hashing than traditional methods?

When is it appropriate to use RFC2898DeriveBytes versus a typical hash? Update I now understand that a KDF is typically used to create a symmetric key for possible use in encrypting a stream. I ...
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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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6answers
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Does prepending a salt to the password instead of inserting it in the middle decrease security?

I read somewhere that adding a salt at the beginning of a password before hashing it is a bad idea. Instead, the article claimed it is much more secure to insert it somewhere in the middle of the ...
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5answers
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Is this idea for a password manager secure? If so, why doesn't anybody use it? [closed]

I've been thinking of a problem with usual password managers: although they do provide better security than manually using passwords, there's a central database that can get lost, get compromised, ...
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3answers
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Known characters in passwords?

I generate passwords for everything that requires security using the following method: ksoviero@ksoviero-Latitude-E7440:~$ head -c 16 /dev/urandom | base64 gorv/cp+lSiwiEfKck2dVg== 256^16 ...
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3answers
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Should I reject obviously poor passwords?

UPDATE: My questions and concerns below boil down to: "Should I reject obviously poor passwords like 'hellomydarling' or 'password'? My guess is yes and I want to know to what extent. I'm using a ...
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3answers
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Calculating password entropy?

Whenever I look at password entropy, the only equation I ever see is E = log2(RL) = log2(R) * L, where E is password entropy, R is the range of available characters, and L is the password length. I ...
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3answers
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Can password-protected zip files be broken without brute force?

You have a zip file that you created with 7z to password-protect it with AES 128. Can a smart adversary extract the data only through brute force, or is the file vulnerable to other attacks - such as, ...
13
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4answers
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Is it “standard” to SMS passwords?

When I get credentials for a new machine, my company will often send the login id in email, then SMS (or sometimes Skype msg) the password. This is obviously in order to separate the login and ...
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3answers
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What is a good enough salt for a SaltedHash?

Since I'm hashing all passwords with each their own salt, is there a benefit to the salt being really random, or would an incremental counter or a guid be good enough? Also, is there a benefit of ...
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3answers
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Choosing a session ID algorithm for a client-server relationship

I am developing an application which has a client-server relationship, and I am having trouble deciding on the algorithm by which the session identifier is determined. My goal is to restrict ...
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3answers
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Is it safe to generate passwords online?

I usually generate strong passwords using various online tools. Some time ago I mentioned it to a friend of mine and he was shocked that I do such dangerous thing. Is it really so unsafe to generate ...
13
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2answers
326 views

Why is OpenID considered secure when password reuse is not?

OpenID allows you to use your e.g. Google/Facebook/Microsoft account to log into a third party website. It can be used to log into Stack Exchange. Why is this considered an acceptable practice, ...
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6answers
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What is the simplest safe way to convey a password to another person? [duplicate]

What is the easiest way for two people – neither of whom are computer specialists and cannot meet in person – to send a password for an encrypted file that is attached to an email? The two simplest ...
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7answers
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Aren't password managers still incredibly risky?

I understand the utility in having one application remember a bunch of long, randomized passwords, but all you'd need is one well-placed phishing scam or a keylogger and they get all the keys to the ...
13
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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 ...
13
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2answers
214 views

Would suggesting a random passphrase during sign-up hurt overall security?

I've been looking for ways to improve security and security awareness for both internal and external clients and I happened upon the idea of generating a one-time, random "password suggestion" on the ...
13
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1answer
566 views

Is the Litecoin Scrypt hashing technique a threat to hashed passwords?

The Bitcoin alternative, Litecoin uses a different algorithm to protect the block chain, namely Scrypt (not Sha256). Given that GPU accelerators exists, and ASICS are due to be released, does the ...
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4answers
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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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4answers
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How can I make sure password hashing is secure on computers while not being prohibitively slow on mobile devices?

I'm new to cryptography and its implementations. I'm designing an Android app where an user enters a password to retrieve some encrypted data. After some research on possible solutions I ended up with ...
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5answers
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What is the best way to transmit password hash over unreliable TLS?

I have TLS connection between my server and client. I have no certificate, so the connection is susceptible to the Man-in-the-middle attack. I fear that attacker could intercept the password hash ...
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4answers
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Does an *additional* company-wide password offer any real security?

So, let's say a company has what could be referred to as an "access key". Each user has their own username and password, and there is an additional company-wide access key that people must input with ...
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8answers
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What chars should I not allow in passwords?

I am planning to develop a website that require that the users register a username and a password. When I let the user choose a password, what chars should I allow the users to have in the password? ...
12
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7answers
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Why don't we reward users who choose strong passwords? [closed]

Suppose there is a web property that has some sort of reward system or commodity that its users desire. It could be reputation on Stack Exchange-like sites, rank badges on message boards, or add-on ...
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5answers
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How do online accounts get hacked?

How does your typical users run-of-the-mill Facebook/twitter/gmail/AIM/etc account get hacked? Is it simply a matter of a weak password? Are they typically the victim of phishing or other social ...
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4answers
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Handling passwords in a web application

I am trying to learn how a secure web application is developed. Particularly, I am unsure of how passwords are sent from the client to the server. For a typical user/password login form. If the client ...
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3answers
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How can I prevent someone from accessing a Windows XP system via boot disk?

Apparently a computer system protected by a a login password, e.g. Windows XP, can be easily hacked by someone with physical access to it using methods like this one: ...
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4answers
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Why use random salts?

I read this blogpost on how to store passwords in a database, the secure way. Elbert tells us to do this: Generate a random salt and include something random and the username in it. Hash this. Hash ...