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

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1answer
78 views

storing username/email and password with a hash of the hash of the email/password? [duplicate]

Quite the simple discussion this one (one would assume): If I'd hash the email and password, and then hash the hashes, whould this be considered safe enough or would this just be a waste considering ...
0
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2answers
112 views

Password management [duplicate]

I am work in small company. I am Java Developer and Sysadmin of remote servers. I have problem with store password from several servers. How to best way to manage passwords in company?
236
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10answers
27k views

Is my developer's home-brew password security right or wrong, and why?

A developer, let's call him 'Dave', insists on using home-brew scripts for password security. See Dave's proposal below. His team spent months adopting an industry standard protocol using Bcrypt. ...
30
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3answers
31k views

How difficult to crack keepass master password?

How easily could someone crack my keepass .kdbx file if that person steals the file but never obtains the Master Password? Is this a serious threat, or would a brute force attack require massive ...
5
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6answers
703 views

Is it useful to protect hashed password with encryption?

Imagine that I am hashing the users' passwords with a random, long enough, salt, using key stretching, and a secure hash. Would it be more secure to finally encrypt the hash with a symmetric key?
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2answers
106 views

Do I need to salt PBKDF2 when it's used for AES encryption

If I'm using PBKDF2 to stretch a password into a suitable key for use in encryption with AES, should I be using a random salt (for PBKDF2, not the AES IV)?
3
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2answers
310 views

Does bcrypt compare the hashes in “length-constant” time?

I saw this function slowEquals() while reading Salted Password Hashing - Doing it Right, which uses a byte-level xor comparison to avoid timing attacks. I was wondering whether this is what Bcrypt ...
0
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2answers
140 views

Encryption method and other security concerns for a simple password manager [closed]

I thought I would learn a little bit of cryptography programming by making myself a simple password manager program that I can potentially even use to keep track of my passwords. The idea is that my ...
0
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3answers
198 views

How to retrieve the admin's password of a webapp?

I'm doing a pentesting example on a web app and I have dumped all the database. I have a table with the users in plaintext and the passwords hashed. I have to find the admin's password (I know that ...
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5answers
600 views

At what length does a password stop making sense?

I'm going to recommend that our users start using a password manager and start creating strong random passwords. Though I don't know what size of a password to recommend. Is it possible for a ...
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1answer
1k views

How can I avoid sending passwords in plain text when logging into a website?

Suppose that I login to a website. When I type my personal data, aka, password and email, the password is sent in clear text to the server, correct? Then, a network card in promiscuous mode can ...
1
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3answers
215 views

Should I trust my bank after this [closed]

I have just discovered that I can login to my bank with passwords that is not mine. Example: My password is "1234" but I am authorized with all possible post characters. For example "12345" or ...
1
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3answers
315 views

Why not hashing and salting passwords?

When I was implementing my webapp, I decided to hash and salt users' passwords in order to protect them, even though I knew that there will never be a lot of them ... if any. Of course, I'm not saying ...
0
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1answer
125 views

Rainbowtable - Start with plain text [duplicate]

I know how to use rainbow tables. I've already read the other questions this topic here. Well but there is still one question left. As an attacker, I usually have a hash value of a password and ...
0
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2answers
278 views

Recover password or password hash from locked acount.

I have a locked administrator account. Other accounts is unlocked, but it has no rights. I want to get a password from the locked account, or maybe password hash, if possible.
7
votes
6answers
299 views

City Government Emailing User Name and Password

My city has online billing for utilities. When you set up an account they email your user name and password to you. You can't change your password without them emailing it to you again. Isn't this ...
3
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2answers
156 views

Rainbow Tables: What is the Reduction Used for?

This is a follow up from this answer. The answer is very good, and it put me to thinking and doing some research. I have found another good explanation on this site. At some point, the author says: ...
0
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3answers
263 views

Authenticate user without knowing their password

I'm working on a project where each each user will have a public/private RSA key-pair. Users will be able to send encrypted messages to each other using the each target user's public key so that only ...
5
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9answers
1k views

How to easily remember lots of different passwords?

I know that you shouldn’t use the same password on every site. But, when you log into several dozen sites, keeping track of all the passwords can be pretty hard. What system do you recommend that ...
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3answers
702 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 ...
8
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3answers
778 views

Is this code snippet good enough for password hash and salt

After a few days reading up about salting and hashing passwords, I found an actual bit of code that tells how to do it. This is what I found: $blowfish_salt = ...
1
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1answer
1k views

Brute force password cracking with a GPU

How are GPU's provisioned for password cracking? Do all, if not most cracking programs have special GPU aware software or do they just function at the basic driver or API level of the device? Can it ...
16
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4answers
3k views

Password resets - what practices should web services follow?

Many of you may have seen How Apple and Amazon Security Flaws Led to My Epic Hacking, where a Wired reporter's Amazon, Apple, Gmail, and Twitter accounts were successfully hacked. The hacker followed ...
3
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2answers
298 views

From password to key

Can you explain this passage from Wikipedia? When a password (or passphrase) is used as an encryption key, well-designed cryptosystems first run it through a key derivation function which adds a ...
4
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2answers
260 views

Is there a risk in sending the username in a password reset email?

We're using a CMS that has a password reset function that works according to best practices out of the box. Passwords are stored as salted hashes Forgot Password works like this: User enters ...
0
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1answer
139 views

company is sending md5 string via GET['password'] dangerous?

So, this big, reknown company (you all heard off) is sending md5 encrypted strings (with GET key: password) over HTTP. I accidentally came over it since I wanted to use jnlp on a non-windows ...
64
votes
8answers
5k views

Why not allow spaces in a password?

"Your password can't contain spaces." is a message I see from some websites, including 1 . Why? (This question is very similar to Why Not Allow Special Characters In a Password? , but the answers ...
14
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2answers
639 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 ...
54
votes
3answers
11k 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 ...
71
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11answers
7k views

“Username and/or Password Invalid” - Why do websites show this kind of message instead of informing the user which one was wrong?

Lets say a user is logging into a typical site, entering their username and password, and they mistype one of their inputs. I have noticed that most, if not all, sites show the same message (something ...
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1answer
88 views

Password sending through network [duplicate]

In case of no TLS/SSL available, why can't I use the hash of the password (SHA512) as the key to encrypt the password (with out any salt) to send through the network ? MITM attacks I can understand, ...
2
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2answers
347 views

Managing and deploying web app passwords

What are some best practices for managing and deploying web app passwords and private keys? E.g. the password to access a database or external services like the Facebook API. I'm referring generally ...
4
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5answers
506 views

Use the hash of the password to encrypted password

I have a app which transmit the password in clear text. I was planning to use the hash of the password (SHA-512) as the key for encrypting the plain text password. Then send the encrypted text to the ...
8
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3answers
779 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 ...
52
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7answers
26k views

Certificate based authentication vs Username and Password authentication

What are the advantages and drawbacks of the certificate based authentication over username and password authentication? I know some, but I would appreciate a structured and detailed answer. UPDATE ...
46
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8answers
3k views

I'm an IT consultant. Should I discourage a client from telling me his password?

I'm an IT consultant. One client has known me for a few years. He wants me to do some work on his kids' laptop again. I'll need to log into his kids' Windows user account. (I'm guessing that multiple ...
4
votes
4answers
379 views

usernames and passwords

I was thinking about usernames and passwords and I was wondering how secure it would be to instead of the server having a list of usernames and accompanying hash of the passwords, just have a list of ...
8
votes
4answers
1k views

How secure is NOPASSWD in passwordless sudo mode?

On all our boxes we have ssh access via keys. All keys are password protected. At this moment the sudo mode is not passwordless. Because the number of VMs are growing in our setup, we investigate the ...
11
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3answers
8k views

Is a password protected PDF file safe for bank statement attachments?

My bank emails my monthly statement to me in a password protected PDF attachment. Is this a secure method of transmitting something as sensitive as bank statement?
2
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0answers
49 views

Creating New Acc in Mac Mail 1st Connect to Server not SSL is uname & pw tx secure?

It appears that whenever you set up a new mail account on Mac Mail on OS X (or iPhone, iPad etc), that as soon as you enter the server and the mail account user name and password, Mac Apple-Mail tries ...
7
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4answers
648 views

Hash(master + hostname) password scheme for a server pool

I manage about 20+ Linux servers and I am considering using an md5 scheme similar to following to generate the admin passwords: echo 'masterpassword' 'serverhostname' | md5sum Which returns ...
5
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5answers
237 views

Would this idea for a password be secure? [duplicate]

I was thinking about password security this morning. Mainly, about the recent adobe hack releasing thousands of passwords. The current problem with existing passwords is that you have three options: ...
3
votes
1answer
7k views

Where to download a list of email accounts hacked from Adobe? [closed]

Adobe announced they had been hacked and millions of user accounts and passwords compromised. These sites allow a search on email address to see if it was compromised: https://lastpass.com/adobe/ ...
2
votes
4answers
263 views

Should user's password strength be assessed at client or at server side?

Now most of big website like Google mail, Twitter, Facebook have a feature that assesses password strength (check number of digit, alphabet, special characters, or check the similarity over already ...
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3answers
244 views

help me about salting passwords

Eve has just discovered and decrypted the file that associates each userid with its 32-bit random salt value, and she has also discovered and decrypted the password file, which contains the ...
0
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3answers
3k views

Storing passwords online using Gmail documents

Following this discussion about "Online Passwords Managers" I wonder whether it is a good idea to store the passwords using a spreadsheet inside Gmail documents? I mean, it seems to me that these ...
0
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1answer
47 views

Is MS-CHAPv2 incompatible with securely stored passwords?

I have a directory service that can speak a number of protocols and is used for user authentication. Currently user credentials are stored using Bcrypt to protect them in case of a compromised ...
7
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5answers
339 views

Is there any added security benefit to username complexity requirements?

I've come across several sites lately that have complexity requirements for usernames like "must be 8 characters long and contain at least 2 numbers". Is there any real added benefit to this from a ...
1
vote
1answer
526 views

How secure is automatic authentication in Skype?

How secure is checking the automatic authentication option in Skype client? What if I sign in with Microsoft account instead of Skype id? What if both accounts are merged? Is there any documentation ...
8
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1answer
763 views

How to know the windows security dialog asking for username password is genuine?

I recently faced one issue. It appeared my outlook launched a dialog saying it needed password. It looked like this I noticed the "->" character in the domain name which usually it auto fills. Also ...