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

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-3
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2answers
2k views

Is pixel based image encryption secure?

I have encrypted an image using pixel encryption method. I just used a bmp image for that. What I did is, I retrieved each pixel value from the image and obtained the value of red, green and blue ...
14
votes
2answers
542 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 ...
85
votes
8answers
17k 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 ...
3
votes
2answers
197 views

What exactly is the impact on security when forcing user passwords to contain a particular character?

Some years ago a sysadmin of large computing centre (on a campus) enforced the password of every single user to contain the character $ at an arbitrary position. They soon dropped this policy but I ...
5
votes
4answers
2k views

Temporary passwords e-mailed out as plain text

Is this a security issue? Many big ecommerce platform companies use this feature. Where if you forgot your password, they e-mail you a temp password. Could someone potentially figure out the ...
3
votes
1answer
938 views

Pointers for john the ripper rulesets

I've been pouring over the JtR ruleset documentation and making little progress. I understand how to use it to make various permutations from a given wordlist, that's fine. However, I'm trying to ...
11
votes
3answers
1k views

How much information about the reason for an unsuccessful login should a web application give?

After an unsuccessful login attempt, should I inform the user about its reason? Or more generally, how much information about the reason for an unsuccessful login attempt should a web application ...
8
votes
3answers
586 views

Increase the security of an already stored password hash

Right now we're using 1024 byte PBKDF2 with 256 byte user-specific salt and variable iterations. However, I would much prefer to be able to, perhaps once every year or two, to be able to flat out ...
2
votes
2answers
623 views

MySQL Access Control?

I have read somewhere that it is better to have two different MySQL logins in order to prevent hacking. What I mean is having one MySQL login for read access (SELECT permission) and another login for ...
18
votes
7answers
2k views

Are password complexity rules counterproductive?

In creating a login for this site I chose a nondictionary password that would be extremely hard to guess, but easy to remember. I was told that it did not meet complexity rules. After several ...
1
vote
2answers
1k views

Password Protected Zip: if attacker had one file, can use it to decrypt all files?

Consider a folder containing the following files: (file1.txt, file2.doc, file3.pdf) all zipped and password protected, if attacker had one of these file, can use it for decrypting all without knowing ...
202
votes
17answers
17k views

Passwords Being Sent in Clear Text Due to Users' Mistake in Typing it in the Username Field

Upon reviewing the Logs generated by different SIEMs (Splunk, HP Logger Trial and the AlienVault platform’s SIEM) I noticed that for some reason quite a few users tend to make the mistake of typing ...
6
votes
4answers
2k views

Is GPG suitable as part of a password manager and generator?

I assume that GPG is very strong to crack, guess, etc. Since I have confidence in GPG, would it be appropriate to use my GPG key as the master key for a password manager or generator?
5
votes
3answers
979 views

Tools helps: First time cracking passwords

I am trying to crack passwords on two Windows member servers (2003 and 2008). There is no Active Directory. Each user seems to use the same password across servers, workstations, etc. I have access to ...
3
votes
3answers
548 views

Client-Side Hashing to decrease value of password guessing heuristics

Yes, this is 'yet another client-side hashing' question. But, don't leave yet, I think there is some value here. I'd like to do something to mitigate the affect on the community as a whole when my ...
12
votes
3answers
591 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 ...
3
votes
7answers
575 views

How to provide security for passwords stored in Database? [duplicate]

Passwords of end Users are stored in Database which is encrypted (using one way hash like MD5). Apart from me, there are 'other' people belonging to other teams who have access to Database which means ...
1
vote
3answers
583 views

What about fuzzy passwords? For “correct” entry within a margin of error?

I'm wondering if a fuzzy password system would be in any way beneficial to users, or worth implementing. The idea would be that a certain margin of error is acceptable for allowing the user to log ...
3
votes
4answers
4k views

Yahoo Email Keeps Getting Phished

I keep getting spam emails from myself (and I am sending them to others as well) on my Yahoo Mail account. I have already went through two password changes which I thought were secure. My very last ...
3
votes
2answers
2k views

LastPass One Time Recovery Passwords--How?

The LastPass password manager stores One Time Recovery Passwords locally in each browser you use the plugin with: http://helpdesk.lastpass.com/account-recovery/ My question is, how can you have more ...
1
vote
2answers
752 views

What is the safest way to store a password in a single file?

I've been reading about it. This article helped me a lot. But the more I read the more complicated it seems. For example: Is it better to use bcrypt, or PBKDF2, sha2 or something else for the salt? ...
5
votes
1answer
438 views

Need to ephemerally store third-party password

One particular web service that I am writing interfaces with an API. Each API call requires the user's username and password to be sent, no state is maintained. Ideally, when using my web service the ...
6
votes
2answers
3k views

When, exactly, should old password reset tokens be deleted?

I'm trying to figure out best practices for working with password reset tokens. Say a user initiates the password reset process and the are emailed the reset token and we store a hashed copy in the ...
5
votes
2answers
4k views

File security when encrypting files directly with the openssl command / and what about SHA1 hashing password first?

I've been using this command to encrypt files for a while now: openssl aes-256-cbc -a -salt -in secrets.txt -out secrets.txt.enc Then I type in a password. Can someone tell me, roughly speaking, ...
1
vote
3answers
124 views

How to protect against an attack where a person claims to be in a position of authority?

In an office if a person approaches an employee and claims to be a new IT staff and to give them access to their computer, what can prevent this kind of attack? I've worked a couple tech support jobs ...
5
votes
5answers
6k views

Password reset links: random value or authenticated message?

Which is better? Create tamper-proof encrypted password reset token which contains the user id and the expiration time within the encrypted token. Generate a random token and store it in the ...
8
votes
2answers
777 views

How to proceed if a new hash algorithm for passwords is introduced?

I have an e-mail address at a certain institution. A few days ago they sent me an e-mail (in German), which I'd like to paraphrase without revealing the institution: Dear Madams and Sirs, a ...
0
votes
1answer
224 views

What type of attack should be used in order to pass this authentication

I am practicing the Astalavista Wargames and i came across this challenge. The question is: Bob wrote a piece of software but the password verification doesn't seem to work. You must find a way to log ...
2
votes
3answers
145 views

Is password authentication worse that signed messaging if done over SSL?

Let there is a public API: HTTP-based via SSL there are no browsers, just connections between custom written programs The first authentication scheme that came to my mind was... client signs their ...
5
votes
1answer
490 views

How genuine are password entropy calculations?

I apologise for perhaps the confusing title, I'll try and elaborate a little better. Many discussions I see surrounding password entropy focus on the specific context of the range of choices ...
5
votes
2answers
315 views

Passphrase using same word several times

I used a trivial 3-letter dictionary word five times in a row (smth similar to pwdpwdpwdpwdpwd), and am surprised to find my self in the list of hacked accounts in a penetration test using a ...
6
votes
1answer
806 views

How does SRP prevent man-in-middle attacks?

SRP is designed to resist both active and passive attacks, how does SRP prevent man-in-middle and packet modification attacks?
-1
votes
1answer
140 views

What makes EAP-SRP-256 better than SRP? [closed]

What is the advantage of the EAP-SRP protocol? Is it only used in wireless?
12
votes
3answers
2k views

What is the risk and mitigation of accidentally typing a YubiKey password in an open forum?

I have a YubiKey in my laptop (for testing) and accidentally broadcast my YubiKey password out to the Internet. Since this is only a test key, and has no access to anything of value, here are some ...
14
votes
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 ...
2
votes
1answer
320 views

How vulnerable are passphrases with grammatical structure?

Imagine I create a passphrase using random dictionary words but a common grammatical structure (eg: article, noun, verb, adjective, noun). Given a pretty small dictionary of 5000 words, how vulnerable ...
3
votes
1answer
692 views

Pure SRP authentication without TLS

IF using a SRP for client/server application authentication without TLS. Will it be vulnerable to man-in-middle attack, since if using SRP, the public info doesn't really useful to calculate the ...
34
votes
4answers
21k views

Demystifying Web Authentication (Stateless Session Cookies)

I'm currently researching user authentication protocols for a website I'm developing. I would like to create an authentication cookie so users can stay logged in between pages. Here is my first ...
4
votes
3answers
4k views

Email hacking myth

I never believed that some one can actually hack an email that easy. If someone hacks an email it means he actually hacked the server and he will gain access to many emails not to mine only. Anyway ...
1
vote
1answer
156 views

Error using ncrack

I am trying to run a ncrack command of the following format: ncrack -P filePath1 filePath2 --user user1, user2, user3 ipAddress:port and I get the following error; Does anybody know why I'm ...
-3
votes
2answers
926 views

Good Practice: Storing Passwords in general

I've got a totally theoretical question to you on today - what is the "best" practice for storing passwords? [Best in terms of security and performance] Usually, especially PHP-Developers tend to ...
5
votes
2answers
5k views

Why doesn't Microsoft implement salt on users passwords in Windows?

Pretty straightforward - So we use rainbow tables to get passwords of users out of hashes. So why won't Microsoft implement salt on the passwords in Windows to be hash(password+salt)? Won't this ...
1
vote
0answers
41 views

Database hash for password field [duplicate]

I'm using a mysql database and am looking for a cryptographic hash method for a password with salt added to it. What would be the best hash method for this problem?
2
votes
1answer
2k views

Using John the Ripper to crack SHA hash w/ partial knowledge

Group, I have a SHA1 hash that I would like to brute-force. I have knowledge of several characters before and after the password (ie, if the hash is derived from "xxxpasswordyyy", I know both xxx and ...
4
votes
4answers
817 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
1answer
385 views

Saved passwords (use case)

I have a program in which a user enters a password, and the user data is stored encrypted using AES-128. The data and passwords must be stored together. Both the data and the password are encrypted ...
-6
votes
1answer
590 views

Secure Web application Password vault/manager [duplicate]

I would like to build an open source online password vault which allows users to securely store their passwords, like Keepass or roboform, but where a user can access their passwords through a ...
3
votes
2answers
396 views

Fixing the high-bit problem in PHP's crypt() implementation

I'm working on a site that has to have compatibility with older versions of PHP, which suffer from a high-bit issue in the Blowfish crypt() implementation. Essentially, non-ASCII characters are not ...
9
votes
3answers
3k views

Encrypting user data using password and forgot my password

I am planning to do a web application which stores a lot of personal stuff (info, photos...). And to give users a sense of protection, I want to encrypt the data before storing it to the database. ...
1
vote
2answers
5k views

Is there a way to find out how long it takes John the Ripper to crack a particular password?

I am looking to test/demonstrate things like: when the supplied wordlist contains "abc123" and pw="abc123" then John cracks the pw in 1/2 a second... but if word list does not contain "abc123" John ...