An attack using every possible input to attempt to produce the correct output. Typically the method of last resort when no weakness allows the use of a more restricted input set. E.g. trying all possible (or likely) passwords, in an attempt to guess the correct one.

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14
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3answers
21k views

Why does Hydra return 16 valid passwords when none are valid?

I've been playing around with Hydra and DVWA and I've hit a bit of a snag - Hydra responds letting me know that the first 16 passwords in my password list are correct when none of them are. I assume ...
95
votes
11answers
13k views

How critical is it to keep your password length secret?

Is keeping your password length secret critical to security? Does someone knowing that you have a password length of say 17 make the password drastically easier to brute force?
45
votes
4answers
66k views

How to estimate the time needed to crack RSA encryption?

How to estimate the time needed to crack RSA encryption? I mean the time needed to crack Rsa encryption with key length of 1024, 2048, 3072, 4096, 5120, 6144, 5120, 7168, 8192, 9216, 10240, 11264, ...
31
votes
8answers
5k views

Do non-keyboard characters make my password less susceptible to brute forcing?

I can put characters in my password for which there are no keys on a keyboard. On Windows, Alt+#### (with the numpad) inserts the character for whatever code you type in. When I put this in a ...
22
votes
5answers
6k views

What's the practical limit for rainbow-table based bruteforce?

Say we have a hash of a password. The password can be considered to be made of of totally random characters and has a fixed length of N. The hash is SHA1(password+salt), where the salt is of length M. ...
18
votes
2answers
25k views

Brute Forcing Password to a Truecrypt-encrypted file with Partial Knowledge

A while back, I encrypted a few files with Truecrypt, and stored the password in my head. Now I need to access it again, the password isn't working. I'm sure most of it is right, but I'm off by one or ...
95
votes
9answers
187k 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 ...
-1
votes
1answer
10k views

Has the WPS brute-force cracking issue been fixed?

I have heard a rumor that the WPS brute force attack doesn't work on newer devices, and that you now have to try all 10^7 PINs to find the correct one. Is that true?
32
votes
7answers
31k views

Invalid users trying to log in to my server

I'm seeing a lot of log entries that appear to be failed login attempts from unknown IP addresses. I am using private and public keys to log in with SSH but I have noticed that even with private ...
22
votes
1answer
3k views

Timing attacks on password hashes

Timing attacks can have a devastating impact in scenarios where the secret is involved, often in cases where byte-wise array comparison is used. Now there are those that advertise using constant ...
6
votes
6answers
14k views

How can I generate custom brute-force dictionaries?

I have found during testing that companies often use variations of their names for critical passwords (for example Microsoft's password might be M1cr0s0f+ or m1cros0ft etc etc). So if I gave it the ...
23
votes
4answers
16k views

how long does it take to actually generate rainbow tables?

I've been reading up about rainbow tables as I think they're quite interesting cause they're actually a pretty simple concept. Anyway, I was wondering, has anyone been involved in actually generating ...
3
votes
3answers
852 views

Calculate time taken to break AES key

A 256 bit AES key is required to be broken using the brute force method on a 2GHz computer. How long would it take to break the key in the best case and in the worst case situations? Assume that 1000 ...
6
votes
4answers
759 views

Can't brute force password cracking somehow be throttled?

Online articles mention the importance of a strong password and suggest that hacking tools allows bad guys to attempt millions of passwords per second. I am wondering why OSes and websites and such ...
55
votes
8answers
9k views

Am I experiencing a brute force attack?

When checking the auth log of a server with the command: grep sshd.\*Failed /var/log/auth.log | less I see thousands of lines like this: Jan 12 11:27:10 ubuntu-leno1 sshd[8423]: Failed ...
42
votes
4answers
31k views

Are salted SHA-256/512 hashes still safe if the hashes and their salts are exposed?

Scenario: a database of hashed and and salted passwords, including salts for each password, is stolen by a malicious user. Passwords are 6-10 chars long and chosen by non-technical users. Can this ...
26
votes
2answers
20k 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 ...
16
votes
5answers
70k views

How to generate dictionary for a dictionary attack?

I need to crack my own password. Advantage is that I know possible characters and maximum length. What I need is to create a dictionary. The dictionary should contain all the combos of characters ...
5
votes
1answer
725 views

Perfectly Robust Hashing Scheme, or Completely Over-Engineered?

This is going to get long, so prepare. Basis of the question is, Do all these steps improve security, or am I completely overthinking the problem? Are my assumptions/thought process valid? We all ...
9
votes
3answers
2k views

Wordpress Brute Force Attacker knows real admin Username -

I've noticed a brute force attempt on several different Wordpress installs that know the right admin user name for those respective sites... It seems very strange that the hacker would be able to ...
12
votes
1answer
771 views

General purpose slow/unique hash routine for dup checking of private data, without storing the data itself?

I am wondering if there is a percentage of uniqueness known to be lost with every repeat of various hash routines, like MD5, SHA1, and how that might compare with other algorithms. If theoretically I ...
1
vote
3answers
286 views

How to (further) ensure SSH security?

I set up my Linux Ubuntu machine as an SSH server through no-ip.com and it works great. Recently I discovered the command, sudo lastb -ad -F -w which outputs a log of the most recent failed SSH ...
15
votes
2answers
2k views

Are there some good papers (or discussions) on using Markov chains or Hidden Markov Models for password auditing/cracking?

As a programmer and language enthusiast I've been very interested in Markov chains for some time. Considering the influence of natural language on password and passphrase selection (by humans of ...
5
votes
8answers
680 views

Does it take longer to brute force a password starting with z than one starting with a?

I was wondering about the following: If someone tries to get my password with Brute Force, will a password starting with "a" guessed faster than one starting with "z" ? In this case assume the ...
3
votes
2answers
19k views

How long would it take to bruteforce an AES-128 protected pdf knowing the key is 20 letter long and that the charset is A-Z,0-9?

The question says everything, knowing that a pdf is protected using standard Adobe password encryption that comes with Acrobat Pro (which as far as i know is AES 128) how much would it take to ...
7
votes
1answer
15k views

Is my router vulnerable if WPS is enabled but WPS pin code is disabled?

I was reading about Reaver and wi-fi protected setups (WPS). In my Netgear router I have the option to disable the WPS pin code, but still have the WPS push button enabled. Am I secured with such ...
5
votes
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 ...
5
votes
1answer
29k 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 ...
3
votes
1answer
492 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 ...
2
votes
3answers
182 views

Feasibility of time-based database brute-force attacks on websites

I recently learned that there is an attack that utilizes the fact that when brute-forcing a compared string (e.g. hash from a password or token) in a database the query fails a few nanoseconds earlier ...
5
votes
1answer
1k views

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 ...
4
votes
4answers
2k views

Can I brute-force a password hash even if I don't know the hash-algorithm used?

Can I brute-force a password hash even if I don't know the underlying algorithm? For example if I get hold of a database with password hashes and the used hash algorithm is unknown, like a random ...
4
votes
1answer
22k views

Forgot password to 7-Zip archive

I think I already know the answer to this question, but I thought I'd ask the experts anyway. A few months back, I created a password-protected 7-Zip archive which housed the source code of a simple ...
0
votes
2answers
5k views

What are the methods to crack WPA and WPA2? [closed]

Is there any method other than brute force and dictionary attacks to break WPA and WPA2?
-1
votes
1answer
2k views

How long does it take to crack a 100-letter long winrar password? [closed]

i´m interested in how long time it would take for a super computer dedicated to crack to crack a 100-letter long winrar password. The password contains Lowercase, Uppercase, Digits, ...
-4
votes
7answers
2k views

Are passwords made up from concatenating a few foreign words better than shorter random characters? [duplicate]

Does it make sense to insert a foreign word into a paraphrase to mitigate against brute force? For example: "pussiMeansCatInEskimo" "caballoMeansHorse" "CatIsGatto" "SalopeMeansBitch" ...
25
votes
10answers
6k views

Best password strength checker

In XKCD #936: Short complex password, or long dictionary passphrase? Jeff claimed that password cracking with "dictionary words separated by spaces", or "a complete sentence with punctuation", or ...
27
votes
3answers
4k views

Use multiple computers for faster brute force [duplicate]

I've watched Mr. Robot lately and can't stop thinking why it was so hard to decrypt files encrypted using AES encryption with a 256-bit key. Let us say the only method to find the key is through brute ...
20
votes
4answers
5k views

Would allowing shorter passwords sometimes be more secure?

Does the act of requiring certain criteria for passwords make them easier to brute-force? It's always seemed to me that when websites limit the use of "insecure" passwords, it might make it easier ...
18
votes
5answers
684 views

What concrete parameters can I change to make my passphrase-protected private gpg key more secure

There are several questions which discuss the resistance of passphrase-protected private gpg keys against brute force attacks. It seems, this kind of discussion could go on forever. Rather than ...
11
votes
8answers
4k views

With which algorithm I can prevent a brute force on a login?

I want make my software more secure. I want prevent it from brute force attack. I know that a strong password is the best but I can not control it. The algorithm must scale from a very small system ...
16
votes
8answers
1k views

Bruteforce vs Denial of Service

I had a problem presented today which I found quite interesting. You have an application with a management panel. You know some of the accounts as they are standard. You want two things: You want ...
8
votes
5answers
42k views

Is it possible to brute force all 8 character passwords in an offline attack?

This article states: Brute-force techniques trying every possible combination of letters, numbers, and special characters had also succeeded at cracking all passwords of eight or fewer characters. ...
16
votes
5answers
3k views

What is the difference between login throttling and temporary account lockout?

I am currently working on the redesign of a login page. I have initially suggested that login be throttled whereby pauses (incremental - in number of seconds) are introduced between each failed login ...
14
votes
3answers
4k views

Bruteforce attack on my FTP server

I recently setup VSFTPD on my personal server for sharing files over FTP. In the vsftpd.log file, i see hundreds of failed attempts to login with usernames like "adminitrator" , "adminitrator1", ...
12
votes
1answer
581 views

What's an attack's 'computational complexity'?

I'm writing a business-language report about MD5. In my search a found a paper by Yu Sasaki and Kazumaro Aoki explaining their 2123.4 pre-image attack on MD5. I know that it has something to do with ...
6
votes
4answers
2k views

Password entropy in layman's terms

Entropy is a term used often in relation to password security and brute-force attacks, but it is a topic that can get complicated quickly. What is the best way to describe password entropy (what it is ...
5
votes
4answers
5k 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 ...
4
votes
4answers
1k views

Safety of Password Hashing Using bcrypt Done on Client Side

I am currently using a technique where I send the username/password in cleartext (using https) to the server, which then does bcrypt and compares to the db. Standard practice. It is considered safe. ...
2
votes
1answer
9k views

How to use http-get-form in THC-Hydra?

I've been messing with Hydra (Brute Force) to solve the "Damn Vulnerable Web App" brute force section but the problem is when I use http-get-form it said: Warning: child 1 seems to have died, ...