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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55
votes
8answers
89k 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 ...
0
votes
0answers
206 views

Testing Basic Authentication with ncrack

I'm conducting some basic pen testing against a page protected with Basic Authentication. I've sucessfully tested with Medusa and Hydra but am struggling to get the syntax correct for ncrack. the ...
10
votes
2answers
8k 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 ...
30
votes
2answers
35k 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, ...
4
votes
4answers
437 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 ...
1
vote
2answers
171 views

How to make an efficient bruteforce attack on Windows? [closed]

I've been trying to figure out a way to efficiently bruteforce on Windows, but the method I currently have isn't very efficient. I did some profiling and found out that on average it can go through ...
0
votes
0answers
434 views

Brute-Force/Dictionary attack against encypted file using PBKDF2 key derivation

I have been following this very useful post by Thomas. My use case is slightly different. I am developing a mobile application which requires some sensitive data to be stored on the device in a SQLite ...
6
votes
1answer
279 views

Harden a server against mass SSH DoS attacks

How can a Linux server be protected against an attacker that tries to open a large number of SSH sessions (probably trying to brute force a password) that no ports remain to be able to legitimately ...
1
vote
1answer
96 views

Can Hydra crack a flash-based login?

Is it possible to brute force a flash login with hydra? If not, what is a good tool to pen test a flash login?
1
vote
1answer
112 views

Is there an equation to calculate the number of instances of a series of characters exist in a given key space?

If I'm using 16-18 character-length passwords with 94 different possible values-per-character (lower alphas, upper alphas, numbers, and special characters), is there an equation I can use to calculate ...
-3
votes
1answer
49 views

How many possible symbols and punctuations in a password? [closed]

I want to compute the possible combinations of a password consists of 8 digits of: alphabetical letters (26), numbers (0-9), symbols and punctuations. In order to compute this, I have to know the ...
21
votes
5answers
3k 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 ...
3
votes
2answers
17k views

Remove Password Protection from XLS Document

Similar to what is listed here, http://datapigtechnologies.com/blog/index.php/hack-into-a-protected-excel-2007-or-2010-workbook/, is there a way to remove the password from an XLS (Excel 2003) ...
1
vote
3answers
32k views

Wordlists on Kali Linux?

I notice that in /usr/share/wordlists in Kali Linux (former Backtrack) there are some lists. Are they used to bruteforce something? Is there specific list for specific kind of attacks?
2
votes
1answer
124 views

Better than brute-force way to find the “lowest” sha1 hash?

While pointing out a SQL injection flaw on another question, I was able to show that an arbitrary sha1 hash could be inserted into a query such that it would be taken for a real hash, and was ...
1
vote
1answer
110 views

Username Enumeration as a Threat

I have found a Username Enumeration Vulnerability through which I am able to determine whether a particular user is registered with that site. While trying to brute force, after 5 attempts it asks for ...
5
votes
3answers
2k views

What are the odds of brute-forcing an archive with 256-bit encryption?

I have a file (a stand-alone archive). I lost the password to it, but it has been encrypted using 256-bit encryption. The password is some 20-odd characters long (including non-alphanumeric ...
2
votes
1answer
121 views

Given a hash, salt, charset and password length, how do you get the password without brute-forcing it?

I got that question on an exercise and I'm not sure what to answer. Without conventional brute-forcing and without a rainbow table, how could I find out the password? An improved brute-force ...
0
votes
2answers
83 views

How do you overcome the problem of the salt being public and known by the attacker? [duplicate]

I believe that when adding a salt to the password you need to store the values so you can compute the hash again. But, what does happen if the attacker get the salt? How is it possible to add value ...
0
votes
1answer
42 views

Does restarting an encrypted session increase security and deter attacks?

When a user initiates a SSH connection for example, keys are exchanged and a session is established with a new "passphrase" each time. If an attacker were to attempt to brute force this connection, ...
20
votes
10answers
4k 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 ...
11
votes
1answer
13k 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 ...
1
vote
1answer
2k 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
1answer
58 views

Is encryption less resistant to brute-forcing compared to hashing?

I understand that a hashing algorithm like bcrypt uses several rounds of hashing to make it computationally expensive for a brute-force attack. How does encryption work against a brute-force attack? I ...
3
votes
3answers
251 views

Could using a generated key from an online service be considered a risk?

With some colleagues we're having a debate regarding the randomkeygen.com website. I do think that there is a security risk using the generated keys of this (or any of this kind) website. Why ? ...
1
vote
2answers
167 views

How do you know if blowfish key is correct?

Encryption novice here so maybe this question makes no sense... Obviously if you know what the clear text is and it decrypts right, you have it. But if someone is running through keys to break the ...
8
votes
8answers
2k 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 ...
0
votes
1answer
87 views

What is the best way to generate a password/pin like string using brute force method? [closed]

I have a string of 7 characters. I'm supposed to generate all the combinations. But some combinations are more likely than others, I would like the more likely ones to be generated first. If I ...
1
vote
0answers
3k views

Linux Hydra issue - random correct password success

I have an issue with Hydra when i use it. First let me inform that, i read multible guides, tries the excact same command lines as in guides directly supported by the Damn Vulnerable Web Application ...
1
vote
0answers
2k views

BruteForce on Hydra (Usernames or Password with Special-Chars), letter “Ñ”

I use Hydra with the Web-Form (Http-Post-Form); and I'm trying to use a list of Usernames when some of the nicks contain a letter ñ. For example I have the following account in my list: Username: ...
15
votes
3answers
2k views

Why check to see if a password is already used by another user?

This is coming from a joke originally in French: Enter your password. carrot Sorry, your password must be more than 8 characters. carottegéante (giant carrot) Sorry, your ...
1
vote
1answer
1k views

How many possibilities can today's computers check (per second) in a SHA512 hash of a 50-byte-long random entry? [closed]

The problem I want to avoid is "brute force" attacks against a database. So if I add a 50-byte-long cryptographically random salt to my information (which I don't need to retrieve, just its hash) - is ...
-1
votes
1answer
2k views

Hydra bruteforce is giving wrong passwords. Can't seem to work any help? [closed]

Ok so what im actually trying to do is to bruteforce my own account on some website just to check myself . This is NOT for illegal steps or use , im trying to crack my OWN password , and im trying to ...
1
vote
1answer
137 views

What is the strength of the key derivation function on Android device encryption?

What is is strength of the key derivation? Specifically, how many milliseconds or microseconds would it take a desktop computer to check a guessed password to see if it is a match? I am aware this ...
4
votes
3answers
202 views

Is there any reason in particular encryption keys aren't arbitrarily large?

It's my understanding that the more bits an encryption key has, the longer it takes to break the encryption. What is the down side of having a larger encryption key or why don't we see keys of size ...
0
votes
1answer
140 views

How can brute force scripts tell once they're found the correct key?

If you have a random block of data and you encrypt it with a key, how can a brute force script tell when it has found the correct key? Is it possible without some sort of reference to the original ...
19
votes
7answers
15k 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 ...
0
votes
1answer
910 views

Hydra gives wrong answers

Problem: Hydra keeps giving me incorrect passwords every time. I'm using brute-force via Hydra to guess the correct password on a certain website. First of all I used BurpSuite to intercept the page ...
3
votes
3answers
375 views

How to optimize compressed file cracking?

I'm currently doing research on cracking encrypted, compressed files (specifically: uif, zip, 7z, dmg). Looking at all the utilities out there, it seems the time it takes to crack something is ...
6
votes
3answers
584 views

NTLMv2 resistance to bruteforcing

I have a question regarding NTLMv2 resistance to password bruteforcing. I know that some modern graphic processors (like Radeon 6990) are able to calculate billions hashes per second and crack NTLM ...
4
votes
1answer
5k views

Is brute-forcing the only way to crack WPA?

I don't know much about how WPA algorithms work internally. Is brute-forcing an AP the only way to crack WPA? (or to get associated with AP) Another question is about Reaver-WPS, what if an access ...
1
vote
3answers
282 views

Brute Force In Order Or Random?

Which is faster, on average to find the original plain text of a hash: brute force in-order, or with random plaintexts?
8
votes
2answers
5k views

What's the purpose? Strange login attemps “sshd[***] Received disconnect from **.**.**.**: 11: Bye Bye [preauth]”

I've seen something like: sshd[***]: Invalid user oracle from **.**.**.** // 1st line sshd[***]: input_userauth_request: invalid user oracle [preauth] // 2nd line ...
6
votes
7answers
753 views

How can I prevent users from using bad passwords in my web application?

There is a long discussion on whether it's the responsibility of the user or the system administrator to deal with the strength of the password. Obviously, the password is a very private thing, but ...
2
votes
3answers
371 views

Is there an internal equivalent to fail2ban?

fail2ban is a protection against brute-force that locks a user out after a definable maximum failed login-attempts. But if a user already has access to a server with another username already fail2ban ...
0
votes
1answer
5k 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?
3
votes
2answers
142 views

How can you I detect low frequency brute forcing over multiple connections?

While I realize that servers can easily detect brute forcing strategies via a single I.P, it seems that servers would be vulnerable to a distributed attack from a botnet, with each computer attempting ...
3
votes
4answers
20k views

How to generete dictionary for brute force attack?

I need to crack my own password. Advantage is that I know possible characters and maximum length. What I need is to create dictionary for brute force attack. Dictionary should contain all the combos ...
2
votes
2answers
148 views

Slowing down repeated password attacks

I've been reading suggestions to use time-consuming formulas for checking passwords from login attempts, so that repeated attacks will be slowed down. Wouldn't it suffice to just sleep a bit in the ...
2
votes
2answers
3k views

How do you bruteforce decrypt data if you don't know what you are looking for?

If I wanted to brute-force decrypt data, I would try decrypting it with a key and see if the decryption returned nonsense. If the decryption returned meaningful data (ex. something that a natural ...