# Tagged Questions

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.

226 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 ...
2k views

### how long does it take to brute force varying encryption standards?

Let's say I want to encrypt information in a database. What would be the best encryption algorithm to use and why. I was thinking AES, since it's widely used as a government standard, but if the ...
117 views

### Long passwords and key derivation functions

Not being a security expert, I have a rather theoratical question that I have been thinking about for quite a while now: Let's imagine an encryption software that takes a user-provided password, ...
742 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 ...
327 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 ...
215 views

### Can You Brute Force Dropbox Folder URLs?

One can share folders with Dropbox by sending a URL with a hash in it. A recent article reported that user files were accessed by generating urls from common URL shortners. These URLs are typically ...
763 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 ...
338 views

### Do you need more then 128bit entropy

UUID use 128 bit numbers. Currently it is not feasible to randomly produce two UUIDs that are the same. Does that means 128 bits of entropy is suitable for all cryptographic operations? I would ...
199 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 ...
961 views

### Is there any practical attack on port knocking method?

I was wondering, how can I bypass the port knocking method. Is there any public vulnerability or method for attacking port knocking services? For example: I know an SSH port is behind a port ...
2k views

### Brute-force a passphrase, generated by `pwgen 16 -s`, of a GPG CAST5 archive

A sad story: One of our hard drives failed. While it was failing, we managed to take a quick backup. As it is our standard practice, we encrypted the backup using GPG (by however method Duplicity uses ...
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 ...
103 views

### my bruteforce prevention has major downsides - any ideas?

I'm currently searching for the best way to prevent my software's webportal from bruteforce attacks and came up with the following idea: 3 login attempts without any visual challenge after 3 failed ...
163 views

I have been learning metasploit. One thing I noticed was that, all the videos on YouTube, which said "Brute forcing", used a password and a username list. My question is that, won't this be called a ...
3k views

### Cracking MD5 passwords with the same salt

How long would it take to crack passwords up to 10 letters long if you knew the hashes were MD5 with a salt (that you know)?
2k views

Brute-force password cracker programs which claim GPU support include John the Ripper, ighashgpu, oclHashcat, and others. oclHashcat appears one of the more popular, but I am not sure which AMD/ATI ...
255 views

### Cloud services - A window to outsourcing illegal activities?

Recently I was exposed to a number of stories where alleged illegal activities (for this case, we can take brute-force) are outsourced to the cloud, and are run by the cloud providers. The providers, ...
865 views

### Pen test cell-phones

A customer has asked to conduct a pen-test on the phones of employees. The target is text messages in the phones. Text messages are stored on the SIM for security reasons. Physical access to the ...
82 views

### Isn't ssh-copy-id exposing to a brute force attack?

It is a common knowledge, that using keys to authenticate ssh users is more secure than using passwords. However, even with password login disabled, when running ssh-copy-id I am still asked for user'...
451 views

### How can I make wordlist smaller size?

I've been thinking if I create numeric 8chars wordlist and then compress it, can I directly input compressed wordlist into aircrack-ng or is there a way to make a smaller size wordlist, because if I ...
370 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 strength? (PBKDF2 as both ...
202 views

### Are repeating random patterns weaker than non repeating random patterns?

Which would be harder to crack: a password comprising of n characters randomly selected or a password comprising of x randomly selected characters repeated m times so that m*x=n. For example: 9*...
3k views

### How do we estimate the time taken to crack a hash using brute force techniques

A German hacker famously managed to brute force crack a 160 bit SHA1 hash with passwords between 1 to 6 digits in 49 minutes. Now keeping everything constant (hardware, cracking technique - here brute-...
193 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 ...
193 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 ...
1k views

### Can you crack a Mailinator “Alternate Inbox Name?”

From their FAQ: What are "Alternate Inbox Names" ? There are 2 ways to get email into any given inbox. When you check an inbox, listed at the top is the Alternate Inbox name. Emailing that alternate ...
897 views

### Securing anonymous accessible URL with a GUID segment?

In my problem there is an existing system that works as a alerting or clipping service that runs user defined searches and generates results lists. These are setup by authenticated users and this ...
225 views

### ASLR in Ubuntu 11.10

In many of the exploits I see nowadays, brute forcing is a common method of bypassing ASLR on 32 bit machines. However, many of these exploits crash the current process, for example, PHP. Isn't the ...
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, ...
39 views

### How can SHA256-hashes as input to MD5 be revealed?

I know that you shouldn't use unsalted MD5 hashes of passwords in databases. But unfortunately, people do, see https://hashes.org/public.php. From this site I downloaded a file with passwords which ...
421 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 ...
144 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 ...
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?
124 views

### REST Services: Limiting the concurrency of a login endpoint

Scenario: A botnet is recruited to try to authenticate against a website or service with each bot trying infrequently using a common password and a list of 'real' email addresses, avoiding the ...
289 views

### Bruteforcing an iOS PIN

The iOS Security document describes several security mechanisms implemented in iOS 9. I am specifically interested in the actual security of a 4 digits PIN on iOS. I am looking for tangible ...
169 views

### What prevents a coder from brute forcing a wifi?

I know that a coder is able to connect to a wifi through code so my question is: Is there anything that will make it difficult to brute force a wifi password?
67 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 ...
451 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 ...
3k views

I've been trying to use hydra (educational way) but with no success. The site method is http-post but performed by ajax (should it be a problem? I think not). After execute the command I got an output ...
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. ...
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 ...
379 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 ...
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 ...
514 views

### Use brute force to mitigate brute force

Just an idea I had, and I am sure there is a lot of material about this subject, so I am looking for a pointer as to where I can find more information. My idea is this... When storing a password in ...
668 views

### What would be the most efficient way of brute forcing a wifi key [duplicate]

I was wondering how can a brut force of my wifi be prevented so I want to know the best technique that can be used to brute force it first, so protection isn't my question. My question is: What brute ...
634 views

### Known password length, brute force character in place?

We all know that brute forcing is a very slow process and trying all unnecessary possibilities is dumb. By knowing the password length, we can skip trying possibilities of other password lengths and ...
369 views

### Is there something similar to DNSBL's for protecting against forceful browsing?

I want to protect a couple of Apache webservers against forceful browsing. Lately there have been multiple scans querying for non-existent applications on them like phpMyAdmin, notably known for their ...
123 views

### How to protect from DoS on get method?

Suppose I have a website and I want to make sure that a hacker isn't making my server down by utilising a DDOS attack on my website. I thought of getting IP address and revoking the access, but it ...
222 views

### do ISPs implement security measures?

For example, if a user is receiving a denial of service attack, with huge amounts of packets being sent to him to disrupt his service, will the ISP notice and stop the offending traffic? Another ...
434 views

### Seeking advice on how to build a box to brute force hashes? [closed]

I work in a startup security firm, and I need to build a GPU-based to brute force password/hashes, which can be used to validate password strength and test hashing algorithms. I expect some high ...