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

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1answer
187 views

Simple and secure remote installation method that accepts input via a web page?

When installing software on a remote server: Is it possible to let the admin (i.e. the user that installs the software) define admin username and password via a HTML page, in a secure manner? ...
7
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6answers
1k views

Cleartext password in HTML

Is there any problem with outputing a user's password to the HTML in an hidden field (see use case below before flaming xD)? The use case is a registration form with two steps. The user fills in the ...
5
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1answer
197 views

Could a password hash that's prone to more collisions provide better overall security?

Website security breaches seem to be a common occurrence, giving the attacker password hashes that he can conduct a brute force attack against, often given him a list of passwords that will work on ...
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4answers
8k views

HMACSHA512 versus Rfc2898DeriveBytes for password hash

We are currently using HMACSHA512 in .net, with a 128Char (64byte) validation key The salt is 64 char randomly generated string. We allocated 2048 length on the database for the hashed base64 string ...
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3answers
3k views

How to effectively save database password inside desktop application?

Suppose we are in the field of desktop applications which need to store their data in a database. How do I store the password for this database avoiding the most obvious mistakes, which are: 1) hard ...
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3answers
177 views

Do email clients reduce security?

I have recently taken a security course, and have learned a lot about, among other things, the way passwords are stored, etc. Afterwards I was thinking about the way that passwords are stored for ...
105
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3answers
38k views

How does Google Authenticator work?

Google Authenticator is an alternative to SMS for 2Step verification, installing an app on Android where the codes will be sent. It works without any connectivity; it even works on plane mode. This ...
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3answers
1k views

Why one time passwords using nested hash chain are not used?

I am wondering, why web sites do not use one-time passwords generated by hash chain. By that I mean that a client chooses a secret and after being salted, he applies some secure hash function F() on ...
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2answers
605 views

Masking password when typing vs hiding input when typing

There is a command-line application that interactively prompts you for your password to a third-party service. Whereas e.g. sudo completely hides your input as you type your password, this ...
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3answers
1k views

Do users of non-latin character languages suffer from spyware and trojans?

Do Chinese, Japanese, other languages that can't be represented in ASCII get their passwords stolen? I figure there can't be some sort of bruteforce attack software for them, right? Their characters ...
5
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3answers
4k views

Avoiding Brute Force Attacks in a Web Based Login Form

My login form uses Ajax so it doesn't need to reload if the password is wrong. A PHP script process the request and creates the session if the credentials are right. My idea is to have the PHP script ...
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2answers
138 views

Does hash solve passwords in parts?

From an answer this earlier question: Does adding dictionary words to passwords weaken them? "...you have no way to recognize it as a password before testing it (against a hash or an online ...
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1answer
690 views

Why are lengthy passwords stronger than complex ones? [duplicate]

So all my life I've been listening to people tell me to make my password complex: upper case / lower case / numeric / symbols. Recently though I've been reading / seeing that length above all seems to ...
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3answers
2k 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 ...
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2answers
2k views

Web & insecure HTTP - Using RSA for encrypting passwords on the client side

I used client side password hashing in my register and login project. Its purpose is to prevent passive adversaries/eavesdroppers from discovering users' plaintext passwords when HTTP requests are in ...
3
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1answer
230 views

Are there any uses of having a non-deterministic salt value for hashes?

So I've been toying with the idea of having non-deterministic salt values for hashes. Let me explain what I mean: Basically, I applied some properties from Bitcoin including a "difficulty" (ie, ...
3
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1answer
323 views

How to determine hashes/second in password cryptanalysis

I'm working on my dissertation concerning cryptanalysis on password hashes. As part of my research, I aim to crack a number of passwords with John the Ripper and rainbowcrack-mt. I'd like to ...
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3answers
2k views

Does password-protecting a server's BIOS help in securing sensitive data?

I'm running a server of which I protected the BIOS with a password. One doesn't have to enter this password before booting, but before entering the BIOS setup. I just did this from routine. However, ...
11
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1answer
563 views

“Please Enter Nth Character” without HSM

This question has been asked a few times, but always in the format "How does examplewebsite.com implement their 'please enter xth yth and zth characters of your password' function?" And the ...
2
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1answer
310 views

User Authentication API

I'm developing a web API for a user database that will be used to verify a given username / password combination is valid. I'm just looking for comments / criticism on the following method that I'm ...
12
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3answers
13k views

With ASIC bitcoin miners, should SHA256 be considered insecure for password hashing?

I'm sure everyone here has seen the rise and further rise of bitcoin. The process used for mining bitcoin is basically "let's brute force an SHA256 hash that is less than this amount" That being ...
13
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3answers
831 views

How to manage team passwords?

How do most teams handle the storage of passwords, in particular the required changes when team members leave ? Right now, we use a centrally stored encrypted file but the thought of changing 100's ...
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1answer
120 views

Why should I use the VPN? [closed]

Does a Virtual Private Network (VPN) provide an encrypted connection from outside networks or from ISPs to the internal network?
3
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1answer
247 views

Why regenerating a password's hash?

I've read http://alias.io/2010/01/store-passwords-safely-with-php-and-mysql/ on how to store passwords using PHP and MySQL, the secure way. Elbert says: Use a cryptographically strong hashing ...
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5answers
4k views

Why have username AND password? [duplicate]

It seems most security mechanisms nowadays default to a username + password combination for authorization. I want to know why there are 2 "keys," if you will. Won't one credential suffice? Put ...
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6answers
6k views

What's the most secure technique for authenticating user in a website?

I usually ask user for his username and password and run a query over database to return true or false, do you think it's secure enough? do you think it's better to add some steps to procedure?
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3answers
617 views

What is the value in asking for a second password for sensitive operations?

When a user has logged in to a system using their primary password, is there any value in asking for a distinct second password when performing sensitive functions? Does it provide any benefit over ...
3
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1answer
1k views

How does VTP authentication prevent unauthorized access (Can the password be cracked given captured packets)

I know that when setting up VTP across switches in a network you should set a secret/password to prevent unauthorized requests. My question is I know that this uses an MD5 hash to ensure that ...
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2answers
182 views

Does excluding username letters from passwords increase security?

Recently I was asked to change a password, along with a password policy which reqires you to use a digit, a special character and a letter, but forbids any letter from you log in name to be used for ...
14
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6answers
930 views

Is there additional security value in using passwords with words or phrases in non-English languages?

I was thinking about correct horse battery staple. I am not a native English speaker. In my language, the above could be written as: vqrno kon bateriq telbod OR вярно кон батерия телбод. Keep in ...
12
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4answers
3k views

Handling passwords in a web application

I am trying to learn how a secure web application is developed. Particularly, I am unsure of how passwords are sent from the client to the server. For a typical user/password login form. If the client ...
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0answers
45 views

Is it the default in billing systems to send out the users password by email? [duplicate]

I recently made a complaint to a company about them sending out passwords in plain-text via email upon registration knowing that it is a potential security risk. One of their employees responded with ...
15
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2answers
2k views

Password and Generated number - How does it work?

In my company, they don't allow accessing the company email or servers from outside the company network. To access the email from outside the network, you have to use: Username, password and a number ...
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1answer
514 views

Use brute force to mitigate brute force

Just an idea I had, and I am sure there is a lot of material about this subject, so I am looking for a pointer as to where I can find more information. My idea is this... When storing a password in ...
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9answers
5k views

Why improvising your own Hash function out of existing hash functions is so bad

I'm afraid I'll have tomatoes thrown at me for asking this old question, but here goes. After reading that cooking up your own password hash out of existing hashing functions is dangerous over and ...
23
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5answers
2k views

When hashing passwords, is it ok to use the hashed password as the salt?

I don't like this idea. But I can not come up with a technical argument against it. Can somebody explain it to me? The basic idea is: $passwd = 'foo'; $salt = hash($passwd); $finalHash = hash($passwd ...
12
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4answers
2k views

Why use random salts?

I read this blogpost on how to store passwords in a database, the secure way. Elbert tells us to do this: Generate a random salt and include something random and the username in it. Hash this. Hash &...
470
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14answers
80k 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 where I actually care ...
21
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3answers
4k views

Is a password in the clipboard vulnerable to attacks?

I see situations where you may have to input the same password more than once. You may type it in a text editor and copy it to clipboard, to paste it two or more times. In what scenarios this could ...
13
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3answers
14k views

Can password-protected zip files be broken without brute force?

You have a zip file that you created with 7z to password-protect it with AES 128. Can a smart adversary extract the data only through brute force, or is the file vulnerable to other attacks - such as, ...
3
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2answers
7k views

How long it will take to crack a RAR password?

I wonder how long it will take to crack 16 character alphanumeric WinRAR password for a mini supercomputer. As far as I know graphic cards are preferred over CPUs to crack passwords nowadays. If we ...
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1answer
76 views

Parameters in output of password hashing function

A number of encryption functions include their tuning parameters in the output. For example, SCrypt, which I've been considering for an app I'm building, outputs in the following format: $<version&...
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2answers
931 views

user authentication by decrypting a random blob

Normal user authentication is done by comparing "hash"-values. A simple example of this: The user password is hashed with PBKDF2 on the client using a salt (the salt is the hash of the user password ...
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4answers
1k views

Why does getting a password wrong takes more time than not

I type my password to login to Win or Linux. Case 1: I get it right. Almost instant reaction. Case 2: I misspelled it. It takes a while, and then rebounds. Why does it takes longer to identify a ...
12
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2answers
787 views

Zip file with two password

I used this command to password protect a zip file on Linux : zip -P 9000 hash.zip hash.py and it creates the zip file just fine, then I wrote a program to test every possible password on it from 1 ...
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8answers
1k views

How easy is it to find a password in a huge text file?

Say that my password is PASSWORD1 I have a 10MB jumbled text file. I hide my password in two parts in the text, between > and < so I can find it myself. Then I put the 2 parts together and add the ...
2
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1answer
636 views

UUID and Open_id in cookie 'good' enough?

I am using Tomcat 7, jsp to build a small website. I am new to security and it is a school project so using Spring Security is not an option. I am attempting to store UUID and Open_id in the clients ...
6
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1answer
1k views

Reducing password length with hash function

Suppose I would like to use a very long string as a password. As an example we can just say this string is 100 characters in length. However, suppose the application for which I would like to use ...
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2answers
437 views

Is there any way of recover a locked drive using TPM?

Just reading I learned about the TPM technology and how it works. However, it make me wonder... if the motherboard crashes, is the data lost forever? Because you can't use the drive in other system ...
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2answers
21k views

Why are GPUs so good at cracking passwords?

What is it about GPUs that lets them crack passwords so quickly? It seems like the driving force behind adopting good key-derivation functions for passwords (bcrpyt, PBKDF2, scrypt) instead of ...