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

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Cisco IOS question - password management, service password encryption types

I'm university student studying for my certification exam, and I was doing some reviewing today when I found a question that I can't find an answer to. Basically, in the CCNA3 2.4.1 Cisco Netacademy ...
9
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2answers
880 views

Stretching a hash, many iterations versus longer input string

I have been reading up on various password hashing schemes, for example the SHA-based Crypt proposed by Ulrich Drepper and used in some Linux versions. A recurring theme here is to 'strengthen' or ...
9
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4answers
643 views

Should I obfuscate passwords before hashing? Should I pre-hash them on the client? What about salts?

For fun, and in my spare time I'm creating a simple CMS for my own purposes (with hopes to release for wider use... later), using PHP. I'm currently working on the login scheme now, and have a few ...
88
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6answers
30k views

Password Hashing add salt + pepper or is salt enough?

Please Note: I'm aware that the proper method for secure password storage hashing is either scrypt or bcrypt. This question isn't for implementation in actual software, it's for my own understanding. ...
5
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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 ...
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4answers
2k views

Recommended policy on password complexity

Is there any research on how how a password complexity policy can increase or decrease the quality of passwords? If you don't have any requirements on the password then probably 90% of users will use ...
30
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2answers
11k views

HMAC - Why not HMAC for password storage?

Nota bene: I'm aware that the good answer to secure password storage is either scrypt or bcrypt. This question isn't for implementation in actual software, it's for my own understanding. Let's say ...
5
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2answers
1k views

Password History/Password policy

I'm referring to "remembered" password that the domain keeps so a user cannot reuse that password until it has expired in what was set at Password Policy on DC (W2003/W2008). Where is password ...
18
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3answers
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MySQL OLD_PASSWORD cryptanalysis?

The password hash used for MySQL passwords prior to version 4.1 (now called OLD_PASSWORD()) seems like a very simple ad-hoc hash, without salts or iteration counts. See e.g an implementation in ...
5
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2answers
335 views

How can I detect users that have requested AD Administrators to reuse an expired password?

There is a trend among companies I've worked at where administrators (or helpdesk folks) give a user a courtesy extension of the old expired password... rather than forcing the user to change it. ...
14
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4answers
2k views

Looking for example of well-known app using unsalted hashes

Does anyone know of a well-known application that still uses unsalted hashes for password storage? I'm looking for an example for an upcoming lecture on Rainbow Tables, and I think it would add ...
27
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3answers
3k views

Is there any advantage to splitting a password?

I've been reading about the LANMAN (LM) hash and I'm curious about a particular part of the algorithm. The LM hash is computed as follows: The user’s ASCII password is converted to uppercase. ...
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12answers
10k views

How reliable is a password strength checker?

I've tested the tool from Microsoft available here which tests password strength and rates them. For a password such as "i am going to have lunch tonight", the tool rates it's strength as "BEST" and ...
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5answers
2k views

Is Skype secure enough to transmit passwords?

Is it considered "secure" to send a password in a skype message and delete the message after the recipient remembered the password?
11
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3answers
3k 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: ...
22
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4answers
1k views

Why do some sites block pasting into username or password input fields?

I use a few websites that prevent me from copying & pasting into the username or password fields. It's quite frustrating when using a password manager, and if anything I'd think it discourages ...
11
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9answers
2k views

Why do we authenticate by prompting a user to enter both username and password? Does prompting the password only suffice?

I don't know why do we authenticate by prompting the user to enter both username and password. In my mental model, prompting password only suffices. The reason is as follows: Assume there are x ...
9
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3answers
2k views

How can I mitigate the threat that DPAPick poses to my DPAPI protected data?

The Windows Data Protection API (DPAPI) is the suggested method for storing secrets on Windows systems (such as database passwords required by ASP.Net applications). DPAPick was presented at BlackHat ...
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5answers
3k 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 ...
5
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2answers
3k views

Reference implementation of C# password hashing and verification

Does anyone have a reference implementation (ideally 3rd party certified, or government approved) way one-way hash a password for C# and or Java? Ideally,I'd like to see something that includes a ...
3
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2answers
523 views

BlackBerry client authenticating to Java Web Service

I already asked this question at StackOverflow here: http://stackoverflow.com/questions/4970681/blackberry-app-security and was directed to this site, can anyone pitch in as to how I can solve this ...
11
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8answers
2k views

What chars should I not allow in passwords?

I am planning to develop a website that require that the users register a username and a password. When I let the user choose a password, what chars should I allow the users to have in the password? ...
12
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6answers
7k views

Is PBKDF2-based System.Cryptology.RFC2898DeriveBytes() “better” for Unicode Password hashing than traditional methods?

When is it appropriate to use RFC2898DeriveBytes versus a typical hash? Update I now understand that a KDF is typically used to create a symmetric key for possible use in encrypting a stream. I ...
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6answers
396 views

How can I ensure that default passwords are no longer in use?

There are two situations in which 'default' passwords get used on a network: A new user is registered. In her registration pack, along with her new username, e-mail address and so on is her initial ...
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1answer
1k views

Does the Ophcrack LiveCD require hash collection via programs like pwdump?

When I used the Ophcrack LiveCD recently, the program automatically ran without me manually loading any hashes. Question is: If Ophcrack does not automatically find hashes, how can I go about ...
8
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6answers
7k views

One Time Passwords. Using OTP at Windows, Ubuntu and internet sites

my question is this: Is there a way (software,hardware/token or web-ware) to use One Time Passwords in the following scenarios: Logon to my pc/laptop (windows or ubuntu) Logon to sites with OTP ...
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5answers
1k views

Why do some websites and programs restrict password characteristics?

There are some websites and even programs that I use that have rediculous password restrictions. Lots of forums for instance restrict passwords to ~32 characters. Others enforce a restricted charset. ...
65
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8answers
122k views

Where can I find good dictionaries for dictionary attacks?

I’m wondering where I can find good collections of dictionaries which can be used for dictionary attacks? I've found some through Google, but I’m interested in hearing about where you get your ...
6
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2answers
838 views

Storing third-party auth info securely

Suppose there's a multi-user web application that requires access to user's mailbox (on third-party service, like gmail, etc.). This access needs to be persistent. Which means we'd have to store user ...
4
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6answers
875 views

What are the weaknesses of this password-generation-method? How can it be improved?

I recently came up with the problem, that I have much more accounts, than I'm able to remember passwords. I don't want to use a password-safe, because I cannot access it on another computer, I lose ...
34
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9answers
3k 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) ...
8
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5answers
182 views

Citations for inadvisability of globally unique password

I am looking for an authoritative source to back up my position in a disagreement over password policy. I am having a disagreement with a client about the user identification/authentication process ...
12
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4answers
1k views

MS-SQL Password Storage

What would be your recommendation for replacement of an MD5 hash approach to password storage within an MS-SQL database be?
38
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5answers
7k views

Are GUIDs safe for one-time tokens?

I see a lot of sites use GUIDs for password resets, unsubscribe requests and other forms of unique identification. Presumably they are appealing because they are easy to generate, unique, ...
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2answers
2k 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 ...
22
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10answers
4k views

Password Management within an Organisation

Within an organisation there are many passwords such as those for root accounts on servers, hosting accounts, router logins and other such things, that need to be kept track of. I know in some ...
44
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38answers
8k views

What is your way to create good passwords that can actually be remembered?

What are the methodologies which can be used to generate "human" good quality password? They have to ensure a good strength and also easy to remember for a human being.
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8answers
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Retrieving OSx Keychain passwords

I have a computer forensics style osx login.keychain file that I am trying to find the passwords from. I have a very weak mac which I used crowbarkc on to try and brute force but the horsepower is ...
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0answers
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Hints for safe passwords that are easy to remember [duplicate]

Possible Duplicate: What is your way to create good passwords that can actually be remembered? What are good hints to create passwords that are both safe and comfortable? By comfortable I ...
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5answers
2k views

The aescrypt implementation hashes a password 8192 times to generate the key. Is this necessary?

I'm considering encrypting some small files (hundreds of kb apiece) using the aescrypt reference implementation. Looking at the source, it seems that the encryption key is derived from the IV and the ...
70
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13answers
18k views

Why do sites implement locking after 3 failed password attempts?

I know the reasoning behind not letting infinite password attempts -- brute force attempts is not a meatspace weakness, but a problem with computer security -- but where did they get the number 3 ...
15
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7answers
311 views

Is a “security measure” that doesn't provide a security benefit actually harmful?

If a security measure is implemented that doesn't provide any additional security benefit, can it be considered harmful? As an example, consider a login page where the user is asked to enter their ...
27
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4answers
5k views

How secure are my passwords in the hands of Firefox using a Master Password?

I'm relying on Firefox to remember my passwords, using a Master Password of more than 25 characters. How secure is this set-up?
22
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6answers
1k views

Online password managers

Can online password managers be used for storing and managing passwords? I mean from the security point of view. I understand that those systems can be different and some deserves more trust than the ...
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3answers
776 views

If I am obliged to store a password/certificate on a client side, how can i make sure that it is protected?

In certain cases we need to establish a key/password/certificate as a first timer and then as a client we need to use this key/password/certificate to get authenticated. Therefore the ...
332
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11answers
63k views

How to securely hash passwords?

If I hash passwords before storing them in my database, is that sufficient to prevent them being recovered by anyone? I should point out that this relates only to retrieval directly from the ...
37
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9answers
10k 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?
15
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8answers
1k views

Password management/synchronization?

Is there a good enough service I could run on my own home (Linux) server that I could use for storing/accessing/synchronizing passwords so they could be available for me from multiple ...
28
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9answers
17k views

Feeding /dev/random entropy pool?

Which way of additionally feeding /dev/random entropy pool would you suggest for producing random passwords? Or, is there maybe a better way to locally create fully random passwords?
306
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4answers
94k views

Do any security experts recommend bcrypt for password storage?

On the surface bcrypt, an 11 year old security algorithm designed for hashing passwords by Niels Provos and David Mazieres, which is based on the initialization function used in the NIST approved ...