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

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158
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6answers
16k views

How to store salt?

Nowadays, if we expect to store user password securely, we need at least do the following thing $pwd=hash(hash($password) + salt) then store $pwd in your system instead of the real password. I have ...
3
votes
1answer
153 views

How can I store information securely when I can't use crypt or a hash?

I'm creating an application for Google Glass (technically it's Glassware, but whatever). The user will do the following steps when going through setup for the Glassware: Go to my website, redirected ...
2
votes
1answer
78 views

Given a hash, salt, charset and password length, how do you get the password without brute-forcing it?

I got that question on an exercise and I'm not sure what to answer. Without conventional brute-forcing and without a rainbow table, how could I find out the password? An improved brute-force ...
5
votes
3answers
495 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 ...
18
votes
6answers
1k views

How to avoid scripts with hardcoded password? [duplicate]

I have some scripts on Ubuntu Linux machine that logs in to a database server to run some maintenance daily. To login to the database, I need a password and right now it is hardcoded in the script. ...
2
votes
3answers
199 views

What is wrong with a confirmation page displaying my password?

I just registered for a race and the confirmation page gave me the creeps. See below for a screenshot with fake data. I know nothing about internet security. Other than the obvious fact that if I ...
13
votes
4answers
5k views

Confused about (password) entropy

There seem to be many different 'kinds' of entropy. I've come across two different concepts: A) The XKCD example of 'correcthorsebatterystaple". It has 44 bits of entropy because four words randomly ...
8
votes
3answers
2k views

Is LastPass' locally stored One-Time-Password recovery a security problem?

If you forget your LastPass master password then LastPass provides the possibility to recover access to your vault using a One-Time-Password (OTP) which is stored locally but is initially disabled. ...
5
votes
5answers
1k views

How can one secure a password/key in source code [duplicate]

If there is a need for source code to have a password in it, how should this be secured? This is purely an example, but say there is an app that is using an API, and you don't want to expose ...
20
votes
4answers
2k views

What are spambots doing with unintelligible login attempts?

After constantly being under attack in phpBB, I created a new forum by hand, which successfully prevents spam bots from registering, and I get a report for every failed login attempt, telling me the ...
5
votes
1answer
139 views

Why does my bank bother asking basic personal questions to log in to online banking?

To log into my online banking, I have to answer a basic personal question such as "What is your mother's maiden name" or "What is your grandfather's middle name", as well as enter a one-time code from ...
-3
votes
1answer
115 views

How long does it take to break 128-bit key

Hmm, I was asking myself how to compute if we were given one day to try all possible keys for a 32-bit symmetric cypher, how long would it take us to break 128-bit key? My calculations suggest: ...
0
votes
2answers
65 views

How do you protect strings in code from users decompiling them and seeing them [duplicate]

For an example say we have an application such as a client based application which connects to an API using an api key. We are saying for this purpose there is no OAuth. How would a string or in this ...
1
vote
1answer
116 views

Why does Debian security guide recommend md5 hashed passwords?

I am reading the Debian Security How-To and came across a section that I found odd: it recommends to use md5 hashes for /etc/shadow passwords ...
1
vote
3answers
251 views

What is the correct way to make a password salt?

I've made the below function to make a completely random 64 character long hash function password_salt($password){ $salt = hash("sha512", mt_rand(1,100000) . strtotime("now") . $password . ...
8
votes
4answers
950 views

Is 2FA really necessary with long, high entropy passwords?

I was wondering if two factor authentication is really necessary if you are using high entropy, long, unique passwords for each site. From my experience 2fa just beefs up security a little more, by ...
0
votes
1answer
134 views

How could be my skype password stolen? [closed]

My skype password was recently changed. I've changed it back and found it in the internet on hacker's site. My password is pc-generated, like as2fZ12v. How did they manage to hack it, if I've never ...
0
votes
1answer
149 views

Why don't we do dual password instead of forgot password?

You can see a link Forgot Password? nearby almost all login form. As I mentioned in question, Since passwords are completely protected from outside access unless owner reveal, I come up with this ...
1
vote
2answers
191 views

How weak is MD5 as a password hashing function ?

A professor told us today, that MD5 is weak. I understand his chain of thought but pointed out, that IMHO MD5 is a good way to go if you would use a long (even really long) dynamic salts and static ...
0
votes
2answers
113 views

What is truly unbreakable these days? [closed]

Just very curious, count my knowledge in cryptography, algorithms, and security in general as non-existent. Now I am aware that this might be a VERY broad question, but here it goes. What is the most ...
27
votes
8answers
2k views

Is there a method of generating site-specific passwords which can be executed in my own head?

I was thinking recently about password security. My goal is to have mostly random passwords, that are different for each site. But you also should be able to remember them (or re-generate them) ...
1
vote
1answer
399 views

Are post requests secure?

If a post request is sent from a client on a website without SSL, is the request secure? For example, I visit a site badsecurity.com, and I login using a password: Will this password be encrypted ...
1
vote
1answer
129 views

How secure is the PwdHash algorithm and system?

I use the PwdHash service (http://crypto.stanford.edu/PwdHash/) and plugins for pretty much all of my passwords. I believe this is safer because: No service gets the same password as another, so if ...
3
votes
2answers
4k views

How secure is WD MyPassport lock

I have a WD My Passport hard drive. There is an option that allows you to lock your hard drive with a password. How secure is this lock? They don't give details about the encryption algorith or the ...
1
vote
1answer
75 views

Is it a good idea to give users an additional password that they do not control?

It's a given that users will choose bad passwords. Why not help them out? Using a securely-random choice from a large dictionary, choose one or two words and tell the user to write them down. When ...
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?
0
votes
2answers
56 views

How do you overcome the problem of the salt being public and known by the attacker? [duplicate]

I believe that when adding a salt to the password you need to store the values so you can compute the hash again. But, what does happen if the attacker get the salt? How is it possible to add value ...
1
vote
1answer
67 views

What is the best approach for securing log-in credentials on an HTML form?

I realize how basic this question is, but I have relied for years on mechanisms built into .NET to handle log in for me. These days, most of my work involves using client-side logic and calling API ...
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 ...
5
votes
1answer
102 views

Is it okay to normalize unicode passwords with NFC/NFD?

I am currently designing a login for a web service. I will use a PBKDF2 implementation for hashing the passwords. However, I intend to allow unicode for passwords, as I will have international users, ...
8
votes
4answers
479 views

Why does password strength matter?

I understand from a cryptographic standpoint that you want a password to be as random as possible to resist brute force or dictionary attacks. That is fine- but in what circumstances can those ...
16
votes
8answers
9k views

Why do people still use/recommend MD5 if it is cracked since 1996?

It's still commonly recommended way of hashing passwords, even if it's insecurity had been proven in 1996 Therefore we suggest that in the future MD5 should no longer be implemented in ...
33
votes
15answers
5k views

Why do people think that this is bad way to hash passwords?

Well, please tell me, what's wrong with this code: $password = "hello"; $password = md5($password); for($i=1;$i<20;$i++){ $password = md5($password); } It's exactly the same as this one: ...
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 ...
8
votes
5answers
2k views

How to catch a gmail hacker/money-scammer? (in conversation with one right now!)

My friend's GMail account was recently hacked and the perpetrator sent out one of those classic "help I was mugged, I need money" style e-mails. (Edit: I know it's legit; my friend called me to tell ...
19
votes
4answers
2k views

Is using SHA-512 for storing passwords tolerable?

I know that the best options to use for storing passwords are bcrypt/PBKDF2/scrypt. However, suppose you have to audit a system and it uses SHA-512 with salt. Is that "fine"? Or it is a vulnerability ...
3
votes
6answers
391 views

Methods for remembering passwords around the web

What's the least painful way to manage passwords for user accounts that you have on various sites? I see only 3 options: Password manager. Passwords can be different and strong, but the downside is ...
1
vote
0answers
58 views

Rainbow Tables: Why do we need to store the last value of a chain?

Surely we could just make it so a rainbow table says for each beginning of chain do 10k iterations and then we wouldn't have to store both values? Or does by doing it this way it stop collisions? ...
1
vote
3answers
205 views

How to check if our clients were compromised by security breaches in other web applications?

Every now and then a known website is hacked, such as what happened to Adobe or Cupid Media. In such incidents user data is leaked, including usernames, encrypted (and sometimes plain text!) ...
1
vote
1answer
105 views

Retrieve RAR Password through Extracted File

So I was wondering about something, but for the simplicity, consider this example: You have a file with n encrypted files in it, of which one is called 'Note.txt' You also happen to have another ...
1
vote
0answers
54 views

How should I authenticate my SPA frontend with my API since I´ve got no authentication process in the site?

We are designing a web site for selling financial products online. The following is a high level description of the components: Our frontend will be a SPA built with AngularJs. The frontend will ...
0
votes
4answers
215 views

Storing passwords and other data for coworkers

At the moment we are encrypting our server passwords and other important data internal via PGP. Every coworker has got his/her own private key/pass combination set up on their workstation. The problem ...
4
votes
5answers
221 views

Modes of Attack on Time-Bombed Password

I'm one of the co-founders of plaintextoffenders.com. We recently received a submission for which I'm not sure if there is a means of attack or not. The site in question is a hosting/VPS/etc. company. ...
0
votes
4answers
94 views

Is it bad practice to use the same password on different sites?

Is it considered bad practice to use the same password on separate sites, if so why? Even if the passwords to a site are compromised the attacker still doesn't know the user names or sites the same ...
58
votes
10answers
17k views

Bad practice to have a “god” password?

Is it bad security practice to have a password that will allow you to access any user account on a website for support purposes? The password would be stored in a secure manner and would be super ...
10
votes
6answers
20k views

Is howsecureismypassword.net safe to use?

Is it safe to enter my real passwords to test them? I mean, are the entered passwords being recorded/transmitted to someone else?
1
vote
3answers
132 views

Protecting wireless network

My wireless network protected under WPA-PSK/WPA2-PSK protocol. Is there a good reason to change the default user/password for the router management interface? What would it take for an hacker to ...
1
vote
1answer
62 views

Is it possible to hash bcrypt passwords more securely?

I'm wondering if it's possible to increase the work factor of an already encrypted bcrypt password. e.g. I have a password that was encrypted with a work factor of 5, is it possible to increase the ...
1
vote
2answers
67 views

Is it bad to use the same sequence of characters in each password?

A friend of mine purposed a method of making passwords where each has the same base and added to it is something indirectly related to the site or product being signed into. For example all passwords ...
11
votes
5answers
472 views

Security of carrying passwords on person

While in college I decided to have a randomly generated 16 character password. I used parts of that password in various sites. However, one of the sites was compromised so I had to change my password. ...