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

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8
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3answers
5k views

Choosing a session ID algorithm for a client-server relationship

I am developing an application which has a client-server relationship, and I am having trouble deciding on the algorithm by which the session identifier is determined. My goal is to restrict ...
8
votes
5answers
483 views

Utility company does not hash passwords in the database

I had to use my utility company's online account information application and forgot the password. Going through the steps of resetting the password I was emailed the password in the open. I found this ...
7
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4answers
3k views

How to implement a “Remember me” on a mobile app?

I would like to implement a "Remember Me" time-limited auto-login type feature on a mobile application (on Android). To start the app, the user must type in a username and password. For convenience, ...
6
votes
4answers
696 views

Why using 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 ...
6
votes
2answers
760 views

How should I make diceware passphrases more memorable?

I find that truly random diceware passphrase, more often than not, either contain a word that is easily misspelled or has an order that is illogical. I think there are three ways to make a diceware ...
4
votes
1answer
39 views

How to help users manage password portfolios based on risks of compromise?

A framework for modeling password management risks and costs, and the beginnings of a good strategy for users to help them manage passwords for their often large portfolios of accounts is outlined in ...
4
votes
2answers
448 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 ...
4
votes
1answer
381 views

Should password hashes be encrypted or HMACed?

Assume I am hashing user passwords with PBKDF2, bcrypt, scrypt, or some other secure key derivation function. Are there: tangible security benefits, precedents, and respected research for ...
4
votes
4answers
2k views

Are there lists of most common words or ngrams used in passwords and passphrases?

I've been thinking about ways to focus brute forcing dictionary attacks on passwords and passphrases based on the assumption that certain words, combinations of letters, and combinations of words are ...
4
votes
4answers
4k views

Brute force vs other methods of recovering passwords from shadow file

Do you know any good approach for de-hashing/actually bruteforcing hashed passwords in the shadow file? On various operating systems, any good solutions/methods/programs. Or is it better to upload ...
3
votes
3answers
623 views

Encrypting passwords?

I am planning on creating a text file to store my passwords, so I only need to remember 1 password (at the moment, I have about 20 long/complex passwords in my mind, and am worried that I might forget ...
3
votes
3answers
870 views

Best password storage scheme for high entropy, unique passwords which is failure resistant [closed]

What is the best, most secure, easiest way to: store unique, strong passwords for every service which requires authentication make the system resistant (total loss of security is avoided, breaches ...
2
votes
2answers
602 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 ...
1
vote
3answers
288 views

Logic for generating Strong Password?

I try to encrypt password using MD5 but there are decoders for MD5. So I'm worried about encryption of password for big website. Is there any logical suggestion or step function to generate strong ...
24
votes
2answers
1k views

Does versioning an encrypted file make it less secure?

Suppose I use KeePassX as a password manager, and I store the kdb file in Sparkleshare folder as a way for backing up and syncing with multiple devices. The kdb file in itself would be encrypted, but ...
14
votes
2answers
954 views

Salting password with the first 8 bit of the password itself

Do you guys think salting password with the first 8 bit of the password itself will have same result as using stored salt to hash password? [Clarification] I am not storing salt but creating from the ...
14
votes
6answers
560 views

Primary Key as Salt?

Is it okay to use the primary key as the salt in a Users table? The only disadvantage that I can see is if the PK changes (unlikely), then the passwords break. What are your thoughts?
12
votes
3answers
2k views

Password in file .php

My connection.php file stores the credentials to connect to the database. <?php $objConnect = mysql_connect("localhost","username","password"); mysql_select_db("selectDB", $objConnect); ...
11
votes
1answer
380 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 ...
11
votes
5answers
2k views

Is it worth the effort to store FTP passwords encrypted?

I have a project to build a system that needs to push files to multiple third-party FTP servers. I have asked these third parties to provide a more secure interface; all have declined. So now I have ...
10
votes
4answers
1k views

How secure is the SRP that Blizzard uses to protect passwords?

Blizzard very recently announced that their network was compromised, but they assure users in their statement that the password information that the attackers had access to was saved in a secure way: ...
10
votes
5answers
509 views

Security of using passwords or even passphrases to encrypt files

Is it ever appropriate to use real-world passwords to encrypt files to be sent via unsecure means. By real world, I mean a password that is memorable and memorisable by a mere person? I am implying ...
10
votes
2answers
357 views

What problems does this “recover account” procedure have?

On a website I run I have implemented this procedure for account recovery (forgotten password procedure). I would like to know whether there are any issues with it that I have not spotted, that make ...
9
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4answers
472 views

Password security

I was requested at the login page of a website to first change my password. After typing in a new password, the web page told me the new password did not differ enough from the previous one. Does this ...
8
votes
4answers
455 views

How to evaluate the strength of a hashing algorithm?

At work the hashing algorithm we use for passwords appears to be bespoke. Obviously that's a pretty bad idea, but the management don't seem bothered. The algorithm always produces 20 character long ...
8
votes
4answers
3k views

Is it okay for API secret to be stored in plain text or decrypt-able?

Aren't API keys considered usernames and API secrets considered passwords? Why is it that API servers like Amazon Web Services allow you to view your API secret in plain text? It makes me think they ...
7
votes
3answers
341 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 ...
7
votes
1answer
617 views

Reversible password storage obfuscation method for third-party login credentials

I have an internal business application, that as part of its functionality connects to a third-party app using login credentials specific to the user of my own app. These passwords are stored in a ...
6
votes
3answers
796 views

Attack vectors for brute-forcing website passwords

When talking about password security, a lot of discussion centers on the risk of a password being guessed in a brute-force attack. For websites where a user has registered an account, what are the ...
5
votes
2answers
306 views

Can a HSM be used to make password hashing stronger?

Say a database server has a HSM which is in use for encrypting (reversibly of course) credit card numbers. Is there any way a HSM could be used to add strength to a password hashing scheme? (Or are ...
5
votes
2answers
2k views

What algorithms are best be cracked by GPU?

What algorithms are best being attacked by a GPU powered password cracker? For example, I heard that md5crypt that is being used in unix shadow file, is not the best choice for GPU cracking because it ...
4
votes
2answers
464 views

What is the purpose of a Pepper?

I've been trying to find out exactly what a pepper is. The only things I could accurately determine are that a Pepper: Is theoretically unique from site to site and hard-coded in the site's source ...
4
votes
2answers
566 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 ...
4
votes
3answers
615 views

password complexity policy for non “English” passwords

In an internationalized application, what is the best practice for a policy on complexity of passwords? I am not having luck searching for the answer. Wikipedia lists these items for password ...
4
votes
1answer
776 views

Bcrypt as a key derivation function?

I read a lot of entries at stack exchange about bcrypt and why it is supposed to be better than PBKDF2 in terms of password storage. I'm asking now if bcrypt is better than PBKDF2 in terms of key ...
3
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2answers
794 views

Is it a good idea to store Email addresses as hash only?

I am currently building a web service at http://write-math.com similar to http://detexify.kirelabs.org/ that should help users to get LaTeX code from drawn formulae. It is part of my bachelors thesis ...
3
votes
2answers
196 views

What should I do when I need to store passwords for usage in 3rd party software?

I have a desktop WPF application which authenticates with Dynamics CRM 2011. I ask for the username and password of the user and use them to connect to Dynamics CRM 2011 using ...
3
votes
1answer
138 views

Is BSI’s process good? (Informing email address owners that their address/password (of unknown/different accounts) was stolen)

The German BSI (Federal Office for Information Security) claims to have got a list of 18 million email addresses and passwords – supposed to be the result of identity theft. They allow to check if ...
3
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3answers
3k 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 ...
3
votes
4answers
503 views

When hashing passwords, is it okay to store the algorithm used right there in the database?

Since hashing password has become a hot topic recently, it is only natural to expect things to change and assume that some time down the road you might want to replace/tweak the algorithm used in your ...
3
votes
8answers
416 views

Generate user a password instead of asking for one?

I'm trying to weigh the benefits of not allowing users to create their own passwords, but must pick out of a generated selection. Are there any examples of sites that use this approach? Workflow ...
3
votes
1answer
2k views

Please explain Time-step in Time-Based One-Time Password Algorithm

I am studying about OTPs (One Time Passwords). I have gone through all the methods: HOTP (HMAC-based One Time Password), TOTP (Time-based One Time Password) I have no issues with HOTP. But according ...
3
votes
1answer
376 views

Non English password dictionaries

What is a good resource for wordlists used in auditing passwords in non english languages. I have extensive wordlists in English ranging to several GB's, but can't find similar resources for other ...
3
votes
1answer
20k views

How long to brute-force WPA password?

Bob has a password (for his WPA encrypted wifi) which is 8 characters, all lowercase, and not a dictionary word. Eve lives next door to Bob and wants to illegally hack his WPA. The number of ...
2
votes
2answers
224 views

Chinese or “pinyin” wordlists for dictionary attacks

Background: I am currently trying to crack a salted md5 hash which I have recovered from an embedded device running busybox and manufactured in china. I have tried john the ripper using all of the ...
2
votes
3answers
616 views

What is the recomended algorithm to create a key from a password?

In my new secret document encryption utility, the key for symmetric encryption = the hash of a random salt and a user provided password. It is necessary to have a slow hash function in order to ...
16
votes
4answers
900 views

How to treat non-optional bad security questions?

Every once in a while I have to set up an account on a site that, while apparently at least not storing my password in plaintext, still force me to choose from a limited set of security questions that ...
15
votes
4answers
802 views

If a website allows another person to get a list of the site's users passwords, how likely is it that the passwords are stored in cleartext?

We had an incident where some of our managers were given passwords for the people they supervise using a particular company website. Ostensibly it was done so the managers could check in on the users ...
14
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3answers
615 views

What can I do if my bank thinks my date of birth is “known only to me”?

My bank has recently replaced passwords with occasionally asking me information that is "known only to me". Such information includes my date of birth, postcode, and my mother’s maiden name. ...
12
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6answers
1k views

Does prepending a salt to the password instead of inserting it in the middle decrease security?

I read somewhere that adding a salt at the beginning of a password before hashing it is a bad idea. Instead, the article claimed it is much more secure to insert it somewhere in the middle of the ...