A set of requirements regarding password creation, storage, and usage. These requirements often constrain several characteristics of passwords. So, a password policy is a set of rules designed to enhance computer security by encouraging users to employ strong passwords and use them properly.

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280
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13answers
45k views

What technical reasons are there to have low maximum password lengths?

I have always wondered why so many websites have very firm restrictions on password length (exactly 8 characters, up to 8 characters, etc). These tend to be banks or other sites I actually care about ...
64
votes
8answers
5k views

Why not allow spaces in a password?

"Your password can't contain spaces." is a message I see from some websites, including 1 . Why? (This question is very similar to Why Not Allow Special Characters In a Password? , but the answers ...
34
votes
9answers
2k views

Why do password strength requirements exist?

Password strength is now everything, and they force you to come up with passwords with digits, special characters, upper-case letters and whatnot. Apart from being a usability nightmare (even I as a ...
31
votes
9answers
7k views

How long should the password be?

The minimum password length recommended is about 8 characters, so is there any standard/recommended maximum length of the password?
29
votes
5answers
2k views

Are there any guidelines for passwords that need to be read out loud?

I recently saw the movie Olympus Has Fallen. Like in many action movies, at the end a missile is launched, and the hero (Mike Banning, played by Gerard Butler) has 60 seconds to recall the launch in ...
29
votes
8answers
1k views

Who is responsible for the strength of user's passwords?

Who is responsible for a user's password's strength? Is it us (developers, architects, etc.) or the user? As a web developer, I've frequently wondered whether I should enforce the minimal password ...
27
votes
4answers
2k views

Is it safe to show users why their password is not allowed?

/////////////////////////////// Updated Post Below //////////////////////////// This question has received a lot of hits, more than I ever thought it would have on such a basic topic. So, I ...
27
votes
3answers
1k views

Is there a security reason for a site to limit the number of times a user can change their password?

Is there a security reason to disallow a user to change their password as frequently as they want? I have found this security policy in a site and I am not sure why it is enforcing it. One reason I ...
25
votes
12answers
3k views

How secure are passwords made of whole english sentences

I often read as an advice to build strong passwords, just to think about a sentence and then take the initial letters. For example take a nonsense sentence like "I watch Grey's Anatomy at 9.40" gives ...
24
votes
10answers
4k views

Intel How Strong is Your Password page, good advice?

I came across this Intel How Strong is Your Password? page which estimates how strong your password is. It has some advice on choosing better passwords including that you should use multiple ...
24
votes
8answers
6k views

Why Not Allow Special Characters In a Password?

The culprit in this case is a particular (and particularly large) bank. I know one that does not allow special characters (of any sort) in their passwords. Is their any valid reason for doing this? ...
22
votes
6answers
8k views

Sharing wifi at a business - Bad Policy?

Is it safe for a small business to let customers use their wifi while waiting? My friend is starting up a small dentistry practice (1 dentist), and I'm setting up his computers/wifi as a favor. ...
22
votes
5answers
2k views

Do spaces in a passphrase really add any more security/entropy?

I often see passphrase suggestions written as a sentence, with spaces. In that format are they more susceptible to a dictionary attack because each word is on it's own as opposed to a large unbroken ...
21
votes
5answers
2k views

Is it common practice to log rejected passwords?

While selecting unique passwords for each purpose is a great idea, in practice this rarely happens. Therefore many select passwords from a personal pool of passwords that are easily remembered. When ...
19
votes
10answers
3k views

Best password strength checker

In XKCD #936: Short complex password, or long dictionary passphrase? Jeff claimed that password cracking with "dictionary words separated by spaces", or "a complete sentence with punctuation", or ...
18
votes
6answers
2k views

Why do some sites prevent users from reusing their old passwords?

I have always wondered why it is that bad to reuse old passwords; it should not be the end of the world if we happen to use an old password that we previously used. After all, I believe most of the ...
17
votes
7answers
3k views

Why don't people hash and salt usernames before storing them

Everyone knows that if they have a system that requires a password to log in, they should be storing a hashed & salted copy of the required password, rather than the password in plaintext. What I ...
17
votes
3answers
2k 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 ...
17
votes
1answer
754 views

Does a maximum length of password mean non-hashed storage?

When a system requires a password between say 6 and 20 characters in length, does it mean the password is stored without using a hashing function, and that the mysql-field (or similar) is 20 ...
15
votes
4answers
963 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 ...
12
votes
5answers
4k views

Is saving passwords in Chrome as safe as using LastPass if you leave it signed in?

Justin Schuh defended Google's reasoning in the wake of this post detailing the "discovery" (sic) that passwords saved in the Chrome password manager can be viewed in plaintext. Let me just directly ...
11
votes
3answers
2k views

Why are passwords limited to 16 characters?

What is the reason that most websites limit to 16 characters? I would have thought the longer the password the more difficult it makes it for someone to crack it? Is it something to do with hash ...
11
votes
5answers
391 views

What is the best way to hand out passwords to a widely spread diverse employee base?

I have a problem I need to solve - specifically, how to hand out passwords to people in a variety of locations, and with a wide variety of access. I've thought of some options, but there are ...
10
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 ...
10
votes
3answers
525 views

How can I promote good password practices in an organization that doesn't currently care about that?

I work with an organization that uses some very poor practices such as using default user accounts, default passwords (or passwords the same as user accounts), sharing password information between ...
10
votes
3answers
341 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 ...
9
votes
3answers
233 views

Is there any conceivable reason to prevent a password change in an authentication system?

I connect to the VPN of another company with a company-specific username and password (they aren't giving everyone the same password to every company to access it or anything ridiculous like that.) ...
8
votes
4answers
1k 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 ...
8
votes
2answers
377 views

Banning specific passwords?

There have been a couple of questions about enforcing good passwords, so I thought I'd add my own: In addition to enforcing a minimum Shannon entropy, would it generally be a good practice to ...
7
votes
4answers
505 views

Doesn't imposing a minimum password length make the password weaker by reducing the number of possible combinations?

I thought the strength of a password depended on the total number of possible combinations. Therefore, allowing longer passwords should be safer because you then have more possibilities. But why do ...
7
votes
4answers
4k views

Regulations that specify password length?

I have read: PCI DSS 1.2 SOX 404 AR 25-2 ISO 27001 But only PCI DSS specifies a minimum password length. Are there any other regulations that dictate password lengths for any industry? NIST ...
7
votes
4answers
2k views

Is forcing users to change passwords useful?

In many places, there's a policy that force the user changing it's password once a few months. The logic here is, that even if the password have leaked somehow, it'll be abused only for a relatively ...
7
votes
3answers
409 views

Requirement to send username and password in distinct email messages

I have an application that sends username and a password by email (random temporary password, mandatory change on first login). A big customer has this policy of "never send username and password in ...
7
votes
2answers
274 views

Is it a security risk to remind users of the password requirements at login?

I regularly find myself trying to login to websites where I don't remember the password I use. I make some guesses as to what I might have used but usually wind up having to reset it. One thing that ...
7
votes
5answers
472 views

Are we concentrating too much on password complexity?

As a developer and/or user, do I really need to worry about password strength if the system does not allow brute force attack to be feasible (implements a delay or attempt counter) or implements a ...
7
votes
2answers
529 views

Are the SS64.com password generators a good approach?

There are two password generators on ss64.com: The standard one The strong one How they work I made standalone versions of them, plus copy of the original HTML/Javascript versions, if you want to ...
6
votes
7answers
729 views

How can I prevent users from using bad passwords in my web application?

There is a long discussion on whether it's the responsibility of the user or the system administrator to deal with the strength of the password. Obviously, the password is a very private thing, but ...
6
votes
2answers
268 views

What does “Change your password everywhere else” e-mail from compromised service mean?

I've recieved an e-mail from ubuntuforums.org a couple of hours ago: [...] the attacker has gained access to read your username, email address and an encrypted copy of your password from the forum ...
6
votes
3answers
360 views

An alternative to traditional passwords: is there some merit to this idea?

If you've got a website aimed at people that are not neccessarily technically proficient, letting new users choose their own password isn't very secure because of the simple fact that a lot of people ...
6
votes
3answers
294 views

Does prompting for security questions on new computers add any security on banking websites?

When you sign into Bank of America on a computer you haven't used with them before, the site prompts you to answer one of your security questions. How exactly does this make the site more secure? ...
5
votes
9answers
1k views

How to easily remember lots of different passwords?

I know that you shouldn’t use the same password on every site. But, when you log into several dozen sites, keeping track of all the passwords can be pretty hard. What system do you recommend that ...
5
votes
3answers
496 views

Does it make any sense to alter a hashed password? [duplicate]

I've always wondered if it would make any sense to put fake characters into a hashed password? For example this is my password: 1234 and after hashing the password , this is the result: abcd Then ...
5
votes
4answers
1k views

Send new password by email is bad practice but what to do if user forgot his password?

According to http://plaintextoffenders.com/post/7006690494/whats-so-wrong-about-sending-a-new-password-in it's bad so what to do ? Just ask him to set a new one ?
5
votes
2answers
450 views

Requiring regular password change but storing previous paswords?

My bank requires me to change my password regularly but then they can detect if my password was used before. They probably store the old password (possibly hashed) in order to detect it. I think this ...
5
votes
6answers
1k views

Does having a minimum number of digits improve password security?

Some password systems will enforce at least X of a type of character - a common one I see is 'minimum 3 numeric characters'. As far as I understand, simply allowing certain character classes, like ...
5
votes
3answers
384 views

Use of rainbow tables with the NY Times hack?

The NY Times recently published a story about how they were hacked during a four month period. The hacks allegedly were carried out by part of the Chinese military. One part of the story that ...
5
votes
3answers
581 views

Do you think it's a good policy to disclose your password encryption method to users? [closed]

Do you think it’s a good idea to disclose your password encryption policies in your privacy policy or terms of service agreement? In other words, would you tell your users - and the world - you don’t ...
4
votes
3answers
530 views

How often should I reset my salt?

I'm thinking of implementing a salt recycling scheme on my user credentials database. The motivation behind this decision is that even if the attacker manages to get his hands on the database and has ...
4
votes
4answers
498 views

Insecure to require numbers in passwords?

Earlier, I went to a site that required a number and special character, and it got me thinking – wouldn't that make the password easier to brute force? If you assume most passwords have around 12 ...
4
votes
2answers
334 views

How to refute “don't use internet if you don't like it” answer?

I hope it is legit question, similar to, for example, Why do law-abiding citizens need strong security?, et al. and it is tightly conected with user's security, privacy, etc. The response I always ...