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

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17
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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 ...
17
votes
7answers
1k views

My company policy states I must put all passwords in a password safe shared with management. Is this secure?

As the title says, my company has a policy that all passwords to e.g. our workstations and server logins must be stored in an online safe. I won't say which one but there are some out there you can ...
17
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6answers
1k views

Hash function change

I have user account passwords stored in a database using an unsafe (old) cryptographic hash function. What is the best/usual approach to changing password hash function? Only two ideas come to my ...
17
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4answers
974 views

How to treat non-optional bad security questions?

Every once in a while I have to set up an account on a site that, while apparently at least not storing my password in plaintext, still force me to choose from a limited set of security questions that ...
17
votes
5answers
814 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 ...
17
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3answers
3k 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 ...
17
votes
4answers
879 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 ...
16
votes
6answers
4k views

Is my custom password hashing algorithm insecure?

For all of my hobby web projects, I have coded a login system that these projects share. There is no critical data in these projects, the only critical data could be reused passwords. So I try to hash ...
16
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7answers
979 views

Taking password letters not whole one, is this secure? [duplicate]

I found a site which is taking password letters from their users not the whole password. Is this secure? Or do they have saved password as salted hash (MD5)?
16
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5answers
736 views

At what length does a password stop making sense?

I'm going to recommend that our users start using a password manager and start creating strong random passwords. Though I don't know what size of a password to recommend. Is it possible for a ...
16
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2answers
4k views

Why is it always `HASH( salt + password )` that we recommend?

Browsing over this site, many forums, online articles, there's always one specific way we're suggesting to store a password hash: function (salt, pass) { return ( StrongHash(salt + pass) ) } But ...
16
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1answer
1k views

Why does Facebook bother comparing old and new passwords?

An answer to this question says Facebook generates a bunch of password guesses to see if they hash the same as a previous version of the password. Why bother? If a service forces every password to ...
16
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4answers
4k views

Password resets - what practices should web services follow?

Many of you may have seen How Apple and Amazon Security Flaws Led to My Epic Hacking, where a Wired reporter's Amazon, Apple, Gmail, and Twitter accounts were successfully hacked. The hacker followed ...
16
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3answers
8k views

Is bcrypt better than scrypt [duplicate]

Possible Duplicate: Do any security experts recommend bcrypt for password storage? I'm no security expert and do not pretend to be that's why I'm asking here. I write many PHP based ...
16
votes
3answers
962 views

Why do some sites block pasting into username or password input fields?

I use a few websites that prevent me from copying & pasting into the username or password fields. It's quite frustrating when using a password manager, and if anything I'd think it discourages ...
16
votes
2answers
563 views

Bank accepts different password to the one that I set

I'm not particularly well versed in IT security so please bear with me. I recently discovered that my bank's online system will accept passwords that consist of the correct password, and a string of ...
16
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2answers
2k views

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 ...
16
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3answers
2k views

Recommended policy on password complexity

Is there any research on how how a password complexity policy can increase or decrease the quality of passwords? If you don't have any requirements on the password then probably 90% of users will use ...
16
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1answer
3k views

How to apply a pepper correctly to bcrypt?

Update: There is a better way to add a server side key, than using it as a pepper. With a pepper an attacker must gain additional privileges on the server to get the key. The same advantage we get ...
16
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2answers
1k views

Essential things to think about before outsourcing authentication with OpenID, OAuth, or SAML

It's clear there there is no consistent set of features among any of the popular authentication providers. Below is an attempt to aggregate the similarities and differences I've noticed, but I ...
15
votes
7answers
665 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 ...
15
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12answers
2k views

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 ...
15
votes
6answers
5k views

My IP address (with a NAS) is targeted by a hacker. What to do? Should I be worried?

I've noticed, based on the logging of my NAS, that my IP address is targeted by a hacker. I already took action by automaticly ban the IP address permanently after five unsuccesful login attemps. ...
15
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3answers
526 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
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6answers
977 views

Appropriate password requirements for a login (OpenID) service/provider/delegate/thing

This is with regards* to Stack Exchange's upcoming OpenID provider (and in particular, discussion about password requirements). Currently, password requirements are: Must contain 3 of: lower case ...
15
votes
4answers
816 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 ...
15
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4answers
1k views

My credit union is reducing its maximum password length to 10 characters

I just received an email from my credit union saying they are redesigning their online banking service and that I will need to change my password by October 22 to conform to the new limit of 10 ...
15
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8answers
974 views

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
304 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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5answers
2k views

The aescrypt 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 aescrypt reference implementation. Looking at the source, it seems that the encryption key is derived from the IV and the ...
15
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3answers
531 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 ...
15
votes
2answers
804 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
votes
4answers
555 views

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 ...
15
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4answers
255 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 ...
15
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1answer
4k views

Can a dictionary attack crack a Diceware passphrase?

Everyone knows the words used in Diceware passwords (all 6^5 = 7776 words are published) -- they're all common words. Everyone seems to know that we're not supposed to use dictionary words for ...
15
votes
2answers
542 views

Can client-side hashing reduce the denial-of-service risk with slow hashes?

When storing user's passwords that you need to verify against (but not use as plaintext) the current state of the art is: Hash the password Use a salt Use a slow hash function - bcrypt, scrypt, etc. ...
14
votes
2answers
966 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 ...
14
votes
6answers
978 views

Is This Login Security Enough?

I'm coming up with my next login system for admins of an ecommerce website to have login form is SSL secured password is converted to sha256 before being transmitted (bcrypt is too slow still for ...
14
votes
2answers
2k views

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 ...
14
votes
5answers
865 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?
14
votes
7answers
1k views

Why should I hash passwords?

I've read that every good web application should hash passwords. I found many articles about hashing. So I started implementing hashing on my website and then I asked myself why should I do it? When a ...
14
votes
2answers
739 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 ...
14
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4answers
1k views

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 ...
14
votes
3answers
627 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. ...
14
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11answers
3k 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 ...
14
votes
6answers
676 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
580 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?
14
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4answers
8k 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 ...
14
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2answers
1k views

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 ...
14
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2answers
2k 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?