Requiring clients to solve computational puzzles...

Posted by acidzombie24 on Stack Overflow See other posts from Stack Overflow or by acidzombie24
Published on 2010-05-06T20:51:04Z Indexed on 2010/05/06 21:18 UTC
Read the original article Hit count: 124

Filed under:

puzzle

|

brute-force

Not that I need it, but it was interesting to hear someone speak about their server and protecting it from DOS attack by having a puzzle that the client must solve before the server will do anything (it doesnt do allocations or make a session unless solved).

The person also said puzzles can be made to take a quick amount of time or long. And they are easy to check for correct solutions but difficult to solve.

What are these puzzles? I never heard of one. Can someone give an example (or a link)?

© Stack Overflow or respective owner

Related posts about puzzle

Help with C puzzle

as seen on Stack Overflow - Search for 'Stack Overflow'
I found a site with some complicated C puzzles. Right now I'm dealing with this: The following is a piece of C code, whose intention was to print a minus sign 20 times. But you can notice that, it doesn't work. #include <stdio.h> int main() { int i; int n = 20; for( i = 0;… >>> More
How do I intiailize the vector I have defined in my header file?

as seen on Stack Overflow - Search for 'Stack Overflow'
I have the following in my Puzzle.h class Puzzle { private: vector<int> puzzle; public: Puzzle() : puzzle (16) {} bool isSolved(); void shuffle(vector<int>& ); }; and then my Puzzle.cpp looks like: Puzzle::Puzzle() { // Initialize the… >>> More
8-Puzzle Solution executes infinitely [migrated]

as seen on Programmers - Search for 'Programmers'
I am looking for a solution to 8-puzzle problem using the A* Algorithm. I found this project on the internet. Please see the files - proj1 and EightPuzzle. The proj1 contains the entry point for the program(the main() function) and EightPuzzle describes a particular state of the puzzle. Each state… >>> More
Creating a programming crossword puzzle

as seen on Dot net Slackers - Search for 'Dot net Slackers'
Most programming-related crossword puzzles are generated by computer programs, and consequently lack the design and wordplay which makes New York Times-style crossword puzzles interesting. I decided that I could do better. >>> More
SQL SERVER – Improve Performance by Reducing IO – Creating Covered Index

as seen on SQL Authority - Search for 'SQL Authority'
This blog post is in the response of the T-SQL Tuesday #004: IO by Mike Walsh. The subject of this month is IO. Here is my quick blog post on how Cover Index can Improve Performance by Reducing IO. Let us kick off this post with disclaimers about Index. Index is a very complex subject and [...] >>> More

Related posts about brute-force

Most common account names used in ssh brute force attacks

as seen on Server Fault - Search for 'Server Fault'
Does anyone maintain lists of the most frequently guessed account names that are used by attackers brute-forcing ssh? For your amusement, from my main server's logs over the last month (43 313 failed ssh attempts), with root not getting as far as sshd: cas@txtproof:~$ grep -e sshd /var/log/auth*… >>> More
Brute force characters into a textbox in c#

as seen on Stack Overflow - Search for 'Stack Overflow'
Hey everyone, I am VERY new to programming and the only language I know is C# So I will have to stick with that... I want to make a program that "test passwords" to see how long they would take to break with a basic brute force attack. So what I did was make 2 text boxes. (textbox1 and textbox2)… >>> More
SIP Brute Force Attack Originating From Amazon EC2 Hosts (Amazon unresponsive)

as seen on Internet.com - Search for 'Internet.com'
<b>Building The Net:</b> "I’m sorry, you have reached a company that doesn’t care that we are attacking you..." >>> More
Amazon EC2 SIP Brute Force Attacks on Rise

as seen on Internet.com - Search for 'Internet.com'
<b>VoIP Tech Chat:</b> "Complaints of rampant SIP Brute Force Attacks coming from servers with Amazon EC2 IP Addresses cause many admins to simply drop all Amazon EC2 traffic." >>> More
How to detect brute force in mod-security

as seen on Server Fault - Search for 'Server Fault'
I checked the core rules set in the mod-security but it's didn't contain the rules related to Brute-Force Attack!!! Did anyone know how to write the rules or the existing rules for this kind of Attack! Thanks in advanced, >>> More