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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72
votes
9answers
134k 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 ...
2
votes
1answer
92 views

How much does knowing the zxcvbn password strength help an attacker?

On an answer to the question How critical is it to keep your password length secret?, Mike Ounsworth commented that by storing the zxcvbn-calculated entropy of a password you make it easier for an ...
7
votes
4answers
39k views

Bruteforce on 10 characters length WPA2 password

I'm trying to hack my own WPA2 network for learning purposes. I have the *.cap file generated by aircrack-ng tools after a WPA handshake. I've tested by including my own password and a bunch of ...
1
vote
2answers
33 views

Public/private key auth and VPN

If a server uses public/private key authentication to access SSH, will there be any advantage of restricting the access of SSH over VPN? This link describes both approaches to solve brute force ...
0
votes
2answers
50 views

Brute force time estimation - random sequence

I would like to ask if there are 2^1000 possibilities to choose from, how long would it take go through them all on average? (in terms of min, hours or years) Note: This is not necessary related to ...
1
vote
1answer
38 views

Can Hydra and Crunch be used in combination for HTTP-get-form? [closed]

I'm trying to recover my router username and password without resetting the router for educational purposes. I read that Hydra can be used for "brute-forcing" http-get-form authentication that most ...
29
votes
7answers
4k 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 ...
10
votes
4answers
325 views

What are the drawbacks of login request throttling?

In a web application, one way to protect against password guessing attacks is to lock out accounts after a set number of failed logins. This could be done on both source IP address and username. For ...
80
votes
11answers
12k 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?
1
vote
3answers
60 views

How can hackers access WordPress usernames? [duplicate]

Recently I've had brute force attack attempts on some of my WordPress sites and the attackers are using actual usernames other than the default admin (which was removed). How is it possible for them ...
20
votes
4answers
3k views

How is Gmail susceptible to brute-force attacks?

In the Atlantic article "Hacked!" it says: My wife’s password was judged as “strong” when she first chose it for use with Gmail. But it was a combination of two short English words followed by ...
4
votes
1answer
112 views

Analyzing log files for forensics homework?

Suppose two users have done a murder at 6pm at Dunkin Donuts, I have got the hard disks on site, disk1 and disk2. How do I identify the time and order of each user's activities on the hard disks? ...
4
votes
4answers
477 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. ...
12
votes
1answer
18k 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 ...
5
votes
2answers
179 views

Do I REALLY need to change my LastPass password?

Last weekend LastPass' network was compromised and that a list of email addresses along with the hashes of the master passwords were stolen. It is being recommended that LastPass users change their ...
0
votes
0answers
83 views

Would it take long to brute force a md5 hash like this?

1be8917510-36.51929856278002 10bce1af27-99.18403192423284 103fa11cc6-87.21158325206488 Few examples above and as you can see the pattern is: 1xxxxxxxxx-{a percentage (0-100) to 14 decimal places} ...
23
votes
10answers
5k 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 ...
7
votes
3answers
1k views

Why do we have such big keys?

In Chapter 7 of Applied Cryptography, Bruce Schneier claims that, due to thermodynamic limitations, "brute-force attacks against 256-bit [symmetric] keys will be infeasible until computers are built ...
-1
votes
0answers
30 views

How to perform a hybrid online attack

I understand how dictionary attacks and brute force attacks work. And as far as I get it if I know that the password contains the string "Foo" but might also contain other stuff like numbers, the best ...
7
votes
4answers
5k views

How can hackers guess passwords (using dictionary attack or brute force) without being locked out?

Nowadays almost every website you want to register in; is asking you to create a complicated password...But why cant we use simple passwords? I am just wondering because in case of multiple wrong ...
6
votes
3answers
1k 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 ...
1
vote
2answers
85 views

How much faster does a GPU or FPGA crack an RSA key compared to a CPU?

Are there any significant speed up in time on cracking an RSA key (either brute-force or factoring with general number field sieve) using a GPA or FPGA compared to a CPU? If there is a speed ...
6
votes
3answers
254 views

Is Twitter digits login (sms auth code) insecure?

Twitter released(some time ago) a new kit named Digits which allows the client to login with a phone number and an authorization code (received through sms). I find it great for the user experience ...
17
votes
5answers
493 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 ...
5
votes
5answers
2k views

How unlikely is it that a Google Doc link is guessed?

Most (if not all) of us know that a Google Doc link looks something like this: https://docs.google.com/document/d/13P3p5bA3lslqEJT1BGeTL1L5ZrQq_fSov_56jT9vf0I/edit There are becoming several tools ...
3
votes
3answers
91 views

How is truncation according to PCI DSS secure?

In section 3.3 of the PCI standard, it says that when displaying PANs, limiting visibility to the first 6 and last 4 digits of the PAN is considered secure. Doing some quick math, on a 16 digit PAN, ...
1
vote
1answer
59 views

how to get cookies from aspx site to use it with hydra

I've been playing around with Hydra and .aspx site 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. ...
0
votes
1answer
2k 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 ...
1
vote
1answer
75 views

Brute force a password with a lot of hash (of the same password)

I have a list of approximatively 1000 entities, defined using the following code : list[i] = md5_salt_unix_hash(random_salt, password) Where the random_salt is generated in each iteration and the ...
5
votes
1answer
217 views

Are these access.log entries successful wordpress login attempts?

I am hosting some wordpress sites on an apache 2.4 webserver, and I have discovered thousands of entries in my server logs like this: 221.219.219.248 - - [09/Mar/2015:03:29:25 +1300] "GET ...
13
votes
3answers
13k 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 ...
2
votes
0answers
62 views

Why does Hydra not stop when it finds a password? [closed]

Why does Hydra 8.1 not stop when it finds a password? I am using the -P option with a file that has over 5 Million passwords in it and the correct SSH password is located at approx. line 2100, but ...
0
votes
1answer
735 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 ...
4
votes
0answers
84 views

Random padding in hash functions

In this answer, it was recommended that you add random padding when hashing messages for a trusted timestamp, such as for predictions, in order to avoid dictionary and brute force attacks (at least ...
6
votes
3answers
76k 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?
3
votes
3answers
2k views

How can Facebook possibly stop a bruteforce attack on an account?

I've been doing some research on hacking recently and I found some very interesting tutorials on brute force cracking. I have some questions to ask and I'll be using Facebook as an example. Let's say ...
-2
votes
4answers
162 views

Getting password cracking time and byte storage from bruteforce?

I am stuck with this question, you can see it in the picture I have included below. PARTS (a and b) I know a-z will be 26^8, A-Z will be 26^8 guesses, and 0-9 will be 10^8 guesses. But I can't relate ...
0
votes
2answers
47 views

Library or service for rate limiting credit card transactions by IP [closed]

I have a simple product ordering form. A hacker is attempting to validate stolen credit card numbers by making two orders per minute with a bot. 99% of the orders are declined but some are ...
9
votes
4answers
6k views

In light of the FREAK TLS vulnerability, why do so many servers still offer RSA-EXPORT keys?

Ars Technica is reporting on a new attack against HTTPS. Called FREAK, the devices reported as vulnerable include iPhones, Android devices, and Macs running OS X. The attack (as has been clarified ...
2
votes
2answers
287 views

Temporarily save failed logins password hashes for using against brute force attack

My question is about online brute force attacks, that try to authenticate in the website. 1) For the first case if the requests are coming from the same ip, I think this are relatively easy as after ...
6
votes
2answers
11k views

Is it possible to crack a PIN / PUK code on a phone SIM card?

When deploying a mobile phone best practices policy, one of the points which were raised was the requirement for the user to protect his SIM card with a PIN. The theory is that three failed attempts ...
3
votes
2answers
2k views

Closely spaced failed logins in auth.log

I have a raspberry-pi (running GNU/Linux) and I recently allowed my router to forward port 22 (ssh) to the raspberry-pi so that I could log in while away from home. I then noticed a bunch of ...
5
votes
1answer
7k 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
1answer
102 views

P12 private key vs private key file : what is more secure?

The question is a bit tricky because they don't have the same purpose but : Do both kind of file face the same security issue concerning private key protection : password strenght ? (PBKDF2 as both ...
1
vote
4answers
16k views

Brute-force an SSH-login that has only a 4-letter password

Suppose, you know that a certain computer is only protected by such a short password, then you could just try every possible combination easily. How would a script look like, that tries to crack that ...
4
votes
3answers
17k 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. ...
3
votes
3answers
276 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
2answers
137 views

Realistically, how much added security does having a passphrase on a ssh key have?

Let's assume ssh key brute force is unrealistic. It seems to me your greatest vulnerability would be someone gaining access to a client filesystem. If that's the case then key loggers and a host of ...
2
votes
1answer
48 views

Avoid brute-force enumeration of customers in a SaaS application

I'm involved in the development of a SaaS application. We host the application for different customers. A customer is a company. Each customer gets access to their hosted instance of the application ...
1
vote
2answers
95 views

Circumventing disadvantage of IP-based account lockout

So we're trying to prevent brute-force attacks on our web server login page--currently we just do IP-based locking if x failed attempts from IP address Y occur over z time period. After a security ...