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

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18
votes
2answers
2k views

Does bcrypt have a maximum password length?

I was messing around with bcrypt today and noticed something: hashpw('testtdsdddddddddddddddddddddddddddddddddddddddddddddddsddddddddddddddddd', salt) Output: ...
4
votes
3answers
661 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 ...
1
vote
1answer
533 views

How bruteforce works code wise

I was wondering how bruteforce methods work from a code level. How does the code get access to a login page for example and insert information into the necessary fields? And is the code able to ...
3
votes
2answers
390 views

Is mt_rand() suitable for generating a salt?

Assumed I have to following code in order to generate a random blowfish salt for saving a new password: $blowfishCharacters = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789./'; $salt ...
6
votes
2answers
361 views

Secure password management

I've recently begun using Keepass for my personal password management. I am setting it up to sync between my home PC, work PC and mobile device using dropbox. I'm going "all the way", and have ...
2
votes
2answers
491 views

A protocol to authenticate users without login/password

A casual message exchange on reddit yesterday got me thinking whether it might be possible to design a protocol that removes the need for users to remember a unique password for every service (s)he ...
-2
votes
1answer
488 views

What are some good user login/authentication libraries or protocols to use with Python on Google App Engine? [closed]

I've read elsewhere (http://forums.udacity.com/questions/6028436/bcrypt-not-suitable-for-pythongae) that bcrypt is not suitable for use on Google App Engine. What are some good ways to create a user ...
0
votes
2answers
174 views

Is my domain registrar storing my password in cleartext? [closed]

I called my domain registrar (unnamed here but not difficult to find out and a major provider) about a year ago to have them change some DNS settings. While on the phone, the customer service rep had ...
4
votes
1answer
177 views

Single point of failure: can US government requests for passwords be a vector for attack?

In recent news, CNET has reported requests for passwords, hashing and/or encryption algorithms and salts from U.S. government agencies: The U.S. government has demanded that major Internet ...
4
votes
2answers
629 views

What's the best way to send and receive lots of login credentials?

I'm currently a web developer for a company with lots of different remote clients. There are lots of usernames and passwords that I need to know so that I can do my job. When I first started, I was ...
4
votes
1answer
104 views

Is it acceptable to generate salts with a hash of the username?

Salts are supposed to be unique and randomly generated for each user when storing passwords. Is there a reason why we can't generate these salts with a cryptographic hash function using the username ...
1
vote
2answers
96 views

What is more secure: single long hash, or combination of two shorter?

Fictitious scenario: User accesses a restricted data (available online) identified by random string (supported by captcha to make brute-forcing more difficult). So data is not protected by a ...
8
votes
3answers
919 views

Is this code snippet good enough for password hash and salt

After a few days reading up about salting and hashing passwords, I found an actual bit of code that tells how to do it. This is what I found: $blowfish_salt = ...
5
votes
4answers
2k views

SHA-512 unix passwords. How secure are those hashes, really?

I came across this very alarming sounding thread which indicates a GPU with about half the compute capacity of the GPU currently powering the monitor I type this on is capable of 11.5k c/s. I'm not ...
5
votes
5answers
905 views

Is it a good idea to use an input by the user as SALT?

I have read many Q&As here on IT Security about password hashing and salting. I am building a simple registration form for our community website which will be used by our members to create their ...
2
votes
2answers
173 views

Eye-Tracking, Public Access Points and Password Protection [closed]

Could entering sensitive keyboard input in public places with camera systems equipped with a robust AI possibly leak keystrokes via eye-tracking technology -- assuming the typist is using the ...
-2
votes
1answer
131 views

Can Cain&Able Crack SSL? [closed]

I have been messing around with Cain and Able and used APR on another computer (also mine) to get a hashed version of my username and password for my yahoo e-mail account, but I seem to be lost as to ...
4
votes
1answer
135 views

Is this cross-site password model secure?

I'm looking for a way of securely having passwords for different pages. Say I generate this password: ild23rfsfdfg%*#fArg34t34657%537@asd7oak2094^*q2k2k@Kk3j4tn453Q5# Then, for each site, I change ...
1
vote
2answers
288 views

Why is unshadowing needed?

john /etc/shadow look like working, because john will use many-many CPU for it. But why is unshadowing needed? Why isn't it enough to use "john /etc/shadow"? Because of the salting? Can someone ...
4
votes
2answers
544 views

Would a massive blacklist of guessable passwords be useful? [duplicate]

Suggestions to make a good password all focus on creating a string that a computer (or more likely, a network of computers with multiple GPUs) can not guess. Putting a password meter for when users ...
3
votes
3answers
683 views

How can salted, hashed password storage be combined with a plaintext, nonce and hash based authentication?

My understanding is as follows: To securely store a password (e.g. in a database), you use a hashing algorithm designed for this purpose (designed to be slow, e.g. bcrypt), and you use a unique salt ...
0
votes
1answer
576 views

How do I generate a blowfish password hash in Ubuntu?

What's the command line to generate a blowfish password hash? I can't seem to figure this out at all. Apache's htpasswd only supports bcrypt, and openssl passwd doesn't even do blowfish hahes (but it ...
6
votes
3answers
272 views

Should password be cleared after unsuccessful logon attempt?

Lets assume following workflows a) On a device with keyboard: I type my username and password Press enter [realization] I made a typo Password field is cleared: not a big deal, I can type ...
15
votes
7answers
943 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)?
4
votes
3answers
359 views

Encrypted files storage. How to simplify the password management scheme?

It's probably dublicate but I can't figure out the correct keywords for search. You can help by just telling me those words, I'm rather good with Google :) I want to develop somewhat like file ...
28
votes
3answers
2k 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 ...
4
votes
4answers
394 views

Is a short sudo password ok?

On a server I control, I have disabled password logins (public key only), but still need to enter my password to access sudo. This is becoming cumbersome, as I use a long, automatically generated ...
2
votes
3answers
495 views

Should I take care when entering incorrect passwords in untrustworthy websites?

I have the problem that I usually use 4 passwords that I use quite often. I use the first two strong passwords for very important services (e.g. Email, PayPal,..), and the other two not so strong for ...
8
votes
4answers
740 views

How dangerous is it to store password in plain text on sites like GitHub?

I have a few private repositories set up on GitHub for some of the projects I am working on for my company. These applications connect to databases and I have database authentication credentials ...
6
votes
2answers
437 views

Detecting Pass-the-Hash

I was wondering what you guys are doing to detect attacks like Pass-The-Hash within your network. I've read about Breachbox ...
-3
votes
1answer
388 views

Retrieve Admin Password from router [closed]

There is a way to retrieve a router admin password without hard reset? I'm loggen on LAN and know username and local ip address... TKS
3
votes
3answers
176 views

Are there implementations of password hashing algorithms for major frameworks that utilizes specialized hardware like GPUs/FPGAs?

It is common knowledge that password cracking attempts can greatly benefit from specialized hardware such as large clusters of GPUs or FPGAs. Are there any implementations of the commonly recommended ...
2
votes
1answer
642 views

What are realistic rates for brute force hashing?

I'm trying to gauge password strength assuming that the attacker has a hash of my password. Can anyone cite some realistic contemporary rates at which someone could perform various hashes? I know most ...
0
votes
1answer
305 views

How to encrypt files without giving the user access? [duplicate]

I don't know if I should ask this question on security.SE or stackoverflow, so please move my post if necessary. I want to store my (C#) application data in a way that the user cannot read or modify ...
2
votes
5answers
286 views

Is accepting old passwords a bad policy?

This question is inspired by an experience I had today with online banking, as follows. One year ago I opened an online deposit account. (Without naming the bank, I will say the company is currently a ...
8
votes
3answers
335 views

Does setting a user password on Windows XP help protect against remote exploits compared to no password?

In a typical home user situation with a PC connected to the internet via a router, suppose we are not concerned with protecting the machine from people with physical access. Does setting a password on ...
4
votes
2answers
305 views

Is there a risk in sending the username in a password reset email?

We're using a CMS that has a password reset function that works according to best practices out of the box. Passwords are stored as salted hashes Forgot Password works like this: User enters ...
3
votes
2answers
227 views

How can I create a secure password?

I know the standard tricks, create a long password, numbers, symbols, capital letters, etc. My questions is how do I judge password security. I heard different tricks to make secure passwords. For ...
-2
votes
1answer
613 views

LophtCrack version 6.0.12 is not auditing my Administrator password [closed]

I am using LophtCrack on my Windows 8 OS. I was testing my password strength and the problem I am seeing it is not working. It doesn't reveal my Admin password, I've run the process for half an hour. ...
-1
votes
1answer
215 views

After salting my passwords, are they protected against dictionary attacks? [duplicate]

I use sha1() to hash my users passwords, but recently a friend told me that if someone get the hash then they could use dictionary attack and he recommended using salts. I implemented a random salt ...
7
votes
1answer
848 views

Working out how to decrypt encrypted string when knowing the plain text

I have access to a system which I have been asked to create a data export routine for. However, the address details are encrypted and the original sourcecode/password are lost. However, I am able to ...
-1
votes
1answer
181 views

How can I encrypt my router admin page login session? [closed]

I login to my router using the web connection but the session is not encrypted, is there a third party way to encrypt the web session so no one on my network can sniff the password?
1
vote
0answers
47 views

How can I recover the password of a TrueCrypt vlume? [duplicate]

I am trying to recover the password of a trucrypt volume. It is composed by a combination of 4 words (one invented). I remember 3 of them but not their order. Do you know any tools that cold help me ...
0
votes
1answer
803 views

Why do websites limit password length? [duplicate]

I just made a new account with some eGov service (Belgian government). I use LastPass (which generates long, random strings for each site), But the system told me that the maximum allowed length was ...
3
votes
2answers
193 views

Server checking client's password without ever coming into possession of it

tl;dr: I am wondering what the best way is to check a password when the client does not trust the server. I know of two common ways servers can check if a user's password is correct: The server ...
1
vote
2answers
114 views

How to manage company passwords when employing temporary freelancers?

I am from a marketing firm which now has a development team, which i am part of. We have been tasked with finding a few freelancers who can come in and work when either me and the other developer is ...
7
votes
3answers
556 views

Can cloud based password managing services be trusted?

I'm a big time user of cloud based password managing services like LastPass. But in the light of recent revelations like various government backdoors in popular sites, programs like prism, etc. I'm ...
4
votes
2answers
734 views

What are the security implications of using TOTP for single factor authentication?

(Note: I am not actually planning to do this. This question is strictly theoretical.) TOTP is commonly used as the second factor in Two Factor Authentication. It is an open standard with available ...
-4
votes
1answer
438 views

Feasibility of brute-force on online password [closed]

I am familiar with how offline brute-force attacks work. But for online accounts, assuming no social engineering, how feasible is it to brute-force attack a password? For example, is this dependent ...
46
votes
8answers
3k views

I'm an IT consultant. Should I discourage a client from telling me his password?

I'm an IT consultant. One client has known me for a few years. He wants me to do some work on his kids' laptop again. I'll need to log into his kids' Windows user account. (I'm guessing that multiple ...