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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3
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1answer
115 views

Two factor brute force protection

If I implement two factor authentication using TOTP, I (obviously) have to protect against simple brute force attacks of the TOTP value. If I ask for the TOTP value after successful password login, ...
5
votes
2answers
717 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 advantage,...
-2
votes
3answers
328 views

Hydra producing fake login passwords

I'm trying to "hack" (login) into my own HTTPS website account through Hydra. Therefore, it is 100% legal. Hydra keeps producing tons of incorrect passwords. This is the code I use: hydra -v -V -l ...
5
votes
2answers
7k views

Faster methods for decrypting a TrueCrypt disk, esp. knowing the algorithms used

I encrypted (with TrueCrypt) all my hard drives and had the passwords stored in an encrypted file on my USB disk. The passwords are all (except one) 50 character randomly-generated ciphers, there's no ...
3
votes
2answers
124 views

What scenario are 'extra' strong passwords and hashing algorithms actually protecting against?

Note: I completely understand the need for strong passwords & I understand that there is an issue of speed with hashing. I am just interested in better understanding the actual negative impact of ...
2
votes
1answer
433 views

How does attacker Brute force facebook account if there is a limit for tries? [closed]

I am wondering how does a user use Kali with python Brute Force Algorithm to brute force accounts like a facebook account when there are security measure in place like:Pause your try after 3 ...
0
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0answers
25 views

Cyrus-Imap (v2.3.16) local logon attack

CentOS-6.7 Cyrus-IMAP-2.3.16 The host inet07.hamilton.harte-lyne.ca is our IMAP server host. It offers imap and pop3 publicly. I uses local accounts (/etc/passwd) for imap/pop3 authentication only....
1
vote
2answers
180 views

How can we protect signup APIs from brute force registration?

This is a general question but its prompted by a fairly open API I have for a file storage service that needs to have its front door better locked down. We have an API like POST '/signup' that just ...
46
votes
4answers
69k 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, ...
46
votes
7answers
9k views

How are GPUs used in brute force attacks?

I have read that GPUs can be used in brute force attacks? But how can this be done and is there a need for any other hardware devices (hard disks for instance)? Note: I'm more interested in web ...
1
vote
1answer
96 views

VPN - Why is my NAT'ed Laptop being SSH-brute-forced by External IPs when in VPN?

I am using a commercial paid licence to a VPN provider, which I use on two boxes, a FreeBSD, and a Linux BackBox. When connected to this proxy, my interface receives a public IP from the VPN ...
2
votes
2answers
163 views

How fast is it to bruteforce a 48-bit key with current technology?

Say you have a truly random hexadecimal key formatted as 1234.5678.ABCD, with 48-bit entropy. Assuming the key is stored with no hashing/salting, how fast/easy would it be to brute force it with ...
4
votes
1answer
43 views

What are the dangers of exposing weakly protected user accounts bound with a fake shell over ssh?

As anyone running a server can tell from first-hand experience, there are bots trying to constantly brute force their way through with commonly found usernames over SSH. A friend of mine created a ...
0
votes
2answers
387 views

Cracking a password Protected pdf file using John the ripper

What exactly happens after I provide the hash from the pdf file to John for cracking the password? Does John extract just the password hash from the file and work on it, or is there something else?
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 ...
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?
1
vote
3answers
319 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 ...
19
votes
3answers
3k views

Rate limit login attempts: count by IP or username

I need to limit login attempts. One option is to count attempts by IP address and then block the IP. The disadvantage is that different users may have the same IP address. Another option is to limit ...
0
votes
0answers
36 views

What is a straightforward way to brute force CLI applications?

This is a question to maybe more CTF-experienced guys among you. I wonder how you generally brute force a simple CLI application. For example if you have an application which tells you a user's data ...
2
votes
0answers
55 views

How rf remotes for “cloning” rolling code find matching codes?

I've been tinkering with a rf (garage door) remote control that has a scanner mode (google JMA SR-48 for details). This mode works for Mutancode and Erreka which I assume would be similar to KeeLoq. ...
0
votes
1answer
196 views

Why IOS on IPhone cannot be brute-forced programatically? [duplicate]

I am interested in the recent Apple case where FBI wants to get access, but they say it's not technically possible other than creating a new OS (or I guess just modifying the existing one). More ...
6
votes
2answers
1k views

Apple vs DOJ - how strong is the 10-try wipe brute force barrier?

Out of curiosity and with the hope of helping other beginners and journalists. The current Apple vs DOJ standoff in a nutshell - Apple is resisting DOJ with statements like what they're asking is "...
2
votes
2answers
121 views

Exclude passwords with repeating letters

It would cut down a lot of time of the brute force attack if some of those passwords like "aaaaaa" wouldn't appear. How can this be achieved in Hydra or some other brute force software?
0
votes
3answers
99 views

How does encryption force a processor to “pause”?

I'm often told that encryption forces processors to "make a pause" when performing the math to decrypt a hash, which is why brute forcing can take so long. I don't understand what it means for a ...
19
votes
2answers
27k 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 ...
82
votes
6answers
11k views

Script Kiddies - how do they find my server IP?

I've set up a site on Digital Ocean without a domain yet, so there is only the IP. Despite telling no-one of its existence or advertising it, I get hundreds of notices from fail2ban that various IP's ...
0
votes
1answer
167 views

Brute force a hard drive when most of the password is known

I need to access a hard drive that is encrypted with LUKS. The password provided is incorrect, however it is only incorrect by a character or so. The password itself is very strong and above 30 ...
1
vote
2answers
135 views

Are password-guessing attacks a real threat?

There are tons of questions, answers, articles, papers, cartoons etc. on the subject of how to choose a password in such a way that it's difficult to guess or crack with a dictionary-based attack. I ...
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votes
2answers
267 views

Is it possible to perform bruteforce attack with proxy on a website?

When one does brute force attack online, most probably the person will get caught easily,isn't there a way of doing brute force for example on a website without getting caught?
8
votes
5answers
47k 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. ...
1
vote
1answer
309 views

Law enforcement cracked my phone?

Police took my android phone a few months ago. It was encrypted and had the 10 max tries destruction thing set on. I noticed that yesterday the device disappeared from my android device manager. ...
4
votes
1answer
24k 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 ...
1
vote
1answer
352 views

How to brute force HTTP Basic Authentication requested with XHR?

How can one brute force a website using HTTP Basic authentication using metasploit which uses XHR in background? I am getting error "No URI found that asks for HTTP authentication". Relevant headers ...
5
votes
1answer
320 views

Blocking Chinese IP addresses

I recently checked one of my servers' auth.log file and noticed some very suspicious activity. I recently shut down my server's ssh daemon, so the logs end on Jan 22, but what I noticed after ...
0
votes
1answer
93 views

Can a brute force attack be certainly prevented on a unix/linux shell?

I've been getting kind of curious about computer security. I know brute force has been discussed a fair bit on Stack, but I want to elaborate a bit by asking, "Is it possible to /certainly/ stop ...
2
votes
3answers
771 views

Nmap http-brute - Supplying arguments for bruting via GET

I'm attempting to brute a site in my test lab with Nmap's http-brute nse, which has the URL structure https://192.168.101.6/api/auth?email=a@b.com&password=pass Unfortunately Nmap's official ...
2
votes
1answer
145 views

How does encryption strength make a difference to an attacker

Take for example I have my social security and other personal information stored as a string that I am trying to encrypt on my local drive. My first method of encrypting the string is to use a ...
0
votes
1answer
348 views

How to brute-force WPA-2 password of specific set of characters using oclHashcat?

I want to test oclHashcat on a WPA-2 PSK password of length 8 containing only characters in the set {a-z, A-Z, 0-9}. To do this I have already captured the handshake in a .cap file and converted it ...
7
votes
3answers
3k views

Why is it harder to brute force an iphone than a zip-file?

Having only 1,000,000 possible combinations, an encrypted zip-file with a 6-digit numeric password, could be brute force cracked within a second. But for an iphone (let's say iOS9 if it matters), it ...
56
votes
8answers
10k 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 ...
16
votes
5answers
73k 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 ...
1
vote
1answer
160 views

Yii client side captcha validation

Apparently, Yii web application framework generates some kind of hash value from captcha codes it generates and sends it to the client side so it can be used for client side validation of the captcha ...
3
votes
2answers
212 views

Is there known statistics of passwords used during brute force password attacks?

I have been reading quite a bit about brute force attacks and I am wondering whether the passwords that are used in such attacks should be kept around so as to later prevent my users from having those ...
7
votes
2answers
738 views

Why do so many cracking attempts originate from China?

I recently put a Linux server online and it didn't take long until I had the first attempts to brute-force the SSH login. It's not that I am worried about that - I trust the security of my server. But ...
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 ...
6
votes
4answers
773 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 ...
3
votes
0answers
38 views

Reaver stuck at flow_handler

I tried to run Reaver against my router at home using an Ubuntu 15.10 laptop. The command used was: sudo reaver -i mon0 -b XX:XX:XX:XX:XX:XX -vv -c 7 -a (the channel I got from aerodump-ng). I'm ...
2
votes
0answers
45 views

Customize John The Ripper BF technique

Is it possible for me to customize the way John the Ripper brute forces a .cap file? I, knowing my WiFi password, want to crack it fast as possible (no hit with word list). Can I customize John to ...
1
vote
1answer
88 views

Is it secure to allow an account to use `test123!` as their password?

I'm working on tightening up security for the auth layer of my app and I'm currently making a call on the complexity I'll require for passwords. Is there a 'standard' recommendation for complexity? ...
1
vote
0answers
49 views

trapdoor information with hash functions

I have been playing with an idea for the past few days. I have been unable to find information on here or crypto.stackexchange about using trapdoor information in the input to a hash function. ...