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

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1answer
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Can a Bitlocker To Go user pin be brute forced?

I have a external hard disk and protected a partition on it with Bitlocker To Go. I printed the recovery code but I lost it. I can't remember the user PIN either. If I could only know the first ...
5
votes
2answers
829 views

Best practice for password-protecting a secret key

What approaches are generally accepted for generating a password-protected symmetric key? My intuition is to generate and store a random string of appropriate length as the password-protected key, ...
8
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3answers
4k views

bcrypt: random salt vs computed salt

I'm pretty new to the whole password hashing business, so I might be missing something obvious. I was looking at the bcrypt algorithm, in particular BCrypt.Net, and I was wondering if it wouldn't be ...
-1
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3answers
702 views

find password and iv of an encoded string knowing the decoded string

If I would know the clear and encoded versions of a string could I somehow find the password and.or iv that wore used to encode it? Encoding done with open_ssl aes-128-cbc.
26
votes
6answers
5k views

Why do some sites prevent users from reusing their old passwords?

I have always wondered why it is that bad to reuse old passwords; it should not be the end of the world if we happen to use an old password that we previously used. After all, I believe most of the ...
9
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1answer
3k views

Why does Microsoft limit password length? [duplicate]

Possible Duplicate: Should I have a maximum password length? According to a recent TNW article: Microsoft doesn’t like long passwords. In fact, the software giant not only won’t let you ...
12
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2answers
1k views

Is there any advantage of bcrypt over multiple iterations of SHA-x/MD5?

I know that a good password hashing algorithm should be slow. MD5, SHA256, etc. are fast. So I've been adding multiple iterations of SHA-256 hashing to my web apps (around 50000). Getting the hash of ...
2
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1answer
292 views

What authentication threat data exists?

I recently read an article that said there was not much data on which authentication threat vectors were actually being exploited in the real world. Eg what percent of password theft was by shoulder-...
0
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1answer
358 views

How key_derivation and key_verification functions are implemented of a 7-zip archive's encryption mechanism?

I am curious about how password recovery works for password protected files. And I want to know the exact flow of the 7-zip encryption mechanism :) !! 7-zip uses the AES-256 encryption algorithm in ...
3
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1answer
467 views

DPAPI offline attack by cracking windows password?

I'm thinking of using DPAPI to protect configuration file information in my program. After doing some reading on it, it looks like it uses the user's Windows password as part of the encryption process....
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3answers
577 views

Linux mcrypt security

I just installed 'mcrypt'. When I try to encrypt some file with DES using the command 'mcrypt -a des myfile', I am prompted for a passphrase with a maximum character count of 512. > mcrypt -a des ...
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4answers
2k views

Is encrypting a salt value with a password/plaintext a viable alternative to straight up hashing?

The basic problem, as far as I can tell, is that hashing's flaw is that the password is in the hash. Asymmetric encryption's flaw is that the password is encrypted and can be reversed. The posts ...
2
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2answers
164 views

Is there a term for a “Master + extension” style password scheme?

I personally have (and preach) a password system using a "root" password shared amongst many passwords, plus a unique password component. So for Gmail my password might be correcthorsebatterystaple + ...
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5answers
4k 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 ...
3
votes
2answers
6k views

Password recovery tool over telnet or http basic auth

In my feeble attempt to secure my router, I disabled the service login and either changed the "admin" login and the password, or changed only the password for the "admin" login Normally, I would ...
7
votes
1answer
3k views

Store user passwords in NoSQL database?

I am currently coding the backend of a website and I have not come across an article where this is discussed. I want to store all my application data in MongoDB but I'd like to split out my sensitive ...
7
votes
3answers
823 views

How does KeePass master key derivation increase security?

I don't understand how KeePass key derivation increases the security of the password db at all. First I'll try to explain what I understood from the key derivation described here. I'll use some pseudo ...
5
votes
2answers
17k views

Where/How is an ODBC password stored when 'saved' in Access?

I have been working on a program that uses MS Access and ODBC to connect to an SQL server. One of the requirements is that the user need not know the password for the connection to the SQL server, so ...
26
votes
5answers
5k views

Security impact of using a public password for free WiFi

We have a WiFi network that we want to be public and free. Does having a password that is known to everyone provide any additional security advantage to the people using this network as opposed to ...
17
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2answers
3k views

How secure is Keychain on OS X?

Keychain is a built-in app on OS X that stores all of the user credentials, and allows for one to keep encrypted notes in an easily accessible way. Does anyone know how secure Keychain is? I know ...
2
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2answers
148 views

Is this login authentication safe?

I have been thinking of a way to authenticate users so as to pick out the users using cracked versions of my game from the people who have actually bought it. I came up with this idea: The client ...
6
votes
2answers
3k 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 ...
6
votes
6answers
1k views

What is the use of password encryption?

Why do we encrypt passwords? Is it to protect the password from eavesdropping? to protect the password after saving it in database? both? or for some other reason?
2
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1answer
3k views

Should we block all plaintext authentication and require authentication over an encrypted channel?

Should we configure our servers to require the authentication happen over an encrypted channel and block all methods of unencrypted, plaintext authentication over? I recently configured my servers to ...
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0answers
110 views

How should I manage my passwords? [duplicate]

Possible Duplicate: What is a good practical (and sane) way to manage all your passwords for online sites? So even if I come up with memorable passwords like "correct horse battery staple," I ...
16
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2answers
4k views

What's wrong with storing private keys in the cloud?

I know this sounds like a dumb question, but whats wrong with it? Assuming that all private data is encrypted (by the client) using PBE AES256, then is this scheme more vulerable than storing keys on ...
6
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2answers
1k views

Is it better to hash n*x times in sha1 or n times in sha512 on the client side?

I already know I"m going to hash the user's password n times in either sha512 or n*x in sha1 before it is sent to the server. Once at the server, I'm going to use bcrypt set to use ~1/100th of a ...
7
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2answers
8k views

Help understanding basic user authentication with salts and hashing

I for some reason am not understanding how to execute a secure authentication between client and server for a user. I've read many resources, and I understand how to use the hashing and salting tools, ...
4
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4answers
2k views

SMS Authentication: random OTP or a cryptographic one

I'm adding two-factor authentication using SMS to enhance an existing login process. Since I'm not working with physical tokens, I was wondering what is considered the safest: Sending random 8 ...
7
votes
2answers
441 views

PKCS#5 Salt privacy? [duplicate]

Possible Duplicate: Password Hashing add salt + pepper or is salt enough? In the official documentation of the PKCS5 V2.0 standard, we can read "The salt can be viewed as an index into a large ...
11
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2answers
1k views

Requiring regular password change but storing previous paswords?

My bank requires me to change my password regularly but then they can detect if my password was used before. They probably store the old password (possibly hashed) in order to detect it. I think this ...
4
votes
2answers
189 views

Did I miss anything when checking for passwords?

I was provided with a "challenge" forensics image of 2MB in size (floppy); they provide the disk image and want you to uncover as many passwords as you can find. I downloaded the image and dd'd it to ...
3
votes
1answer
458 views

How strong are google's Application-specific passwords? [duplicate]

Possible Duplicate: Google Account: implications of using application-specific passwords In 2-step verification of google accounts, we need to use the Application-specific passwords generated ...
0
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1answer
139 views

What is a preferred method of security-conscious creation of login cookies [duplicate]

Possible Duplicate: Is it safe to store the password hash in a cookie and use it for “remember-me” login? I am working on a webapp that uses localStorage alone (http://...
3
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1answer
144 views

Password hashing on a load balancing setup

I've been doing some research into password hashing implementations and would like to know if it's feasible to have two servers hash passwords to the same database? I've come across the Bcrypt.net ...
21
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6answers
2k views

Hash function change

I have user account passwords stored in a database using an unsafe (old) cryptographic hash function. What is the best/usual approach to changing password hash function? Only two ideas come to my ...
16
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5answers
1k views

Is it legal to log passwords from failed logins?

Is it legal to store/log mistyped passwords? How many of you have seen this happen in a log file or DB?
6
votes
1answer
610 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 ...
19
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7answers
942 views

Are common passwords at particular risk?

The question Should we disallow common passwords like “password” and “12345”? on User Experience immediately made me think that these common passwords were extremely dangerous not because they are ...
4
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2answers
397 views

How to prove a password guessing theory from Matt Bishop's book “Introduction to Computer Security”

First, this is not a homework problem. This is a problem from Matt Bishop's book "Introduction to Computer Security" which was used as one of the textbooks for a Computer Security class I took last ...
2
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3answers
147 views

How to make an outbound request to users to update their passwords?

Clearly it works best if the request to update a password happens as a response to an inbound request to access a known system, but how do you make an outbound request to users to update their ...
2
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1answer
14k views

Why it does not matter whether you type HEX or ASCII as WEP WiFi password?

I know that I can pass password in HEX as a keyphrase to WiFi network using WEP encryption as well as ASCII. But somehow you cannot get the ASCII when you only know HEX value. Can anyone explain the ...
2
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0answers
97 views

How can a service shorten a password if it is not stored in plaintext? [duplicate]

Possible Duplicate: How can Microsoft validate a shorter password on Microsoft accounts (MSDN)? My Microsoft password was 18 characters long and when I updated to Outlook.com it started to ask ...
6
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3answers
633 views

How can Microsoft validate a shorter password on Microsoft accounts (MSDN)?

I recently ran across this when logging into MSDN. (I saw this screen after typing my initial credentials.) I have a 20+ digit password, however there's apparently a new requirement for Microsoft ...
2
votes
1answer
210 views

IKEv2 in remote access scenarios

Can someone explain why, in remote access scenarios, IKEv2 EAP password-based user auth combined with IKEv2 PUBKEY gateway auth is preferable over mixed IKEv2 PSK/PUBKEY auth using the same password ...
2
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2answers
163 views

Bad planning causing weak passwords

The athletic department at my university has a facebook page and on it they said "the first 500 people to register for this event will get free t-shirts". When registering one has to create an account ...
3
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1answer
1k views

Why do some large companies still store passwords in plain text/decrypt-able format? [closed]

In the last couple of weeks I've come across two fairly large companies who seem to not have stringent password security: Tesco - they store passwords in an "encrypted" format, yet they can decrypt ...
8
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4answers
1k views

Is storing answers to security questions in plain text bad form?

If the input for the security question is completely digital, should the answer to a security question be hashed (or at least encrypted) on the authentication server?
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6answers
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Does having a minimum number of digits improve password security?

Some password systems will enforce at least X of a type of character - a common one I see is 'minimum 3 numeric characters'. As far as I understand, simply allowing certain character classes, like ...
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3answers
4k views

How can I prevent someone from accessing a Windows XP system via boot disk?

Apparently a computer system protected by a a login password, e.g. Windows XP, can be easily hacked by someone with physical access to it using methods like this one: http://www.raymond.cc/blog/...