Linked Questions

30
votes
5answers
5k 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 ...
18
votes
6answers
3k views

What does “random” mean in the context of password creation?

Disclaimer: as you will see from my question I'm a total outsider in this subject, just very curious. I was wondering how easy it would be to crack a password-protected RAR5 file, and I found many ...
28
votes
2answers
4k views

Does password expiry provide any benefit at all (when using randomly generated passwords)?

I have been seeing a shift in password policy, this has been going on for a while (Article from 2017) but I have only just picked up on this. In my organization we expire the user passwords every 90 ...
10
votes
8answers
4k views

Sequential password updates

Let's say I have a reasonable KDF, and that I make users change their passwords periodically and keep some old password hashes to prevent password reuse. What's to stop the user from changing the ...
15
votes
4answers
7k 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 ...
8
votes
3answers
3k views

I found my user details on already old, leaked account information list

I came across an old (>3 years) accounts information list which has been leaked to the web. The list included thousands (>10.000) of account details from a service or services. Apparently the event ...
15
votes
3answers
4k views

How often should passwords change?

I'm asking two very related questions As an admin what policies should be enforced regarding the frequency of password changing? I have an idea that users should be forced to change their password ...
10
votes
4answers
1k views

Is using a flash drive as a base for security a safe thing to do?

I'm developing some software for schools. I've found severe flaws with the current popular school LAN protection that I feel needs fixing so I plan on releasing my own software. One the those ...
12
votes
2answers
2k views

Requiring regular password change but storing previous passwords?

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 ...
12
votes
2answers
7k views

After How Much Data Encryption (AES-256) we should change key?

Considering AES-256 encryption, what is the maximum amount of data should be encrypted with one key? Does Block cipher modes/IV/counters also governs the limit? If say the maximum amount is 50GB, ...
8
votes
2answers
11k views

Password expiration and compliance (ISO, NIST, PCI, etc)

I'm quite confused about what is the current state in 2017 for the idea of password expiration/rotation especially related to security certifications as ISO, PCI, etc. I keep reading that password ...
11
votes
3answers
1k views

Do (uncompromised) passwords ever need changing, if I use a password manager?

For instance, my Google account has a 32-character, random character password that I maintain with LastPass. I regularly flash new ROMs on my phone or otherwise need to be able to manually type in my ...
4
votes
3answers
3k views

Why require new users to change password?

I have noticed that it is common practice when setting up a user account (Windows users accounts and Google Apps user accounts in my case) to require new users to create their own password immediately ...
5
votes
3answers
2k 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 ...
2
votes
2answers
801 views

What impact do the frequency of password resets have on password reuse?

Wondering if there's any research behind the most common password reset cycle I've seen of 90-days, and if there's any research that gives any insight into how to optimize password resets to reduce ...

15 30 50 per page