Security Basics mailing list archives
Re: security in P2P
From: "Rajiv D" <rajiv.ceh () gmail com>
Date: Sun, 29 Jul 2012 08:09:54 +0000
I agree to what Jeff said that MD5 is broken way long time. However we don't see this much in local campuses. Only sophisticated or motivated crackers use these to get through to their victim. One more thing is P2P use chunks and uses these combination to club the full file. If one of the chunk is of wrong size or is simply invalid. The P2P download stops saying size mismatch etc. -- Rajiv -----Original Message----- From: Jeffrey Walton <noloader () gmail com> Date: Sat, 28 Jul 2012 19:19:02 To: <rajiv.ceh () gmail com> Reply-To: noloader () gmail com Cc: Pratik Narang<pratik.cse.bits () gmail com>; <listbounce () securityfocus com>; <security-basics () securityfocus com> Subject: Re: security in P2P On Fri, Jul 27, 2012 at 1:00 PM, Rajiv D <rajiv.ceh () gmail com> wrote:
Hi Pratik, P2P systems uses what is called hashing. Before you can share it on the network it should be hashed. P2P generally uses MD5. So any file that you are downloading should have same hash in all the peers. So if two users have the EXACT same file then only the hash will match and it will be downloaded from them. If some malware has been Introduced in the file then the hash will change and it will be treated as a separate file. The real problem comes when you download from a user and that particular file is malicious. In that case any HIPS can help you out.
Not necessarily - MD5 is broken and should not be used. The same file will hash to the same digest (expected); and different files can hash to the same digest (unexpected). Confer: Flame and the chosen prefix collision attack. Will anyone be surprised when tripwire-like programs are defeated by a sophisticated attacker? Jeff
-----Original Message----- From: Pratik Narang <pratik.cse.bits () gmail com> Sender: listbounce () securityfocus com Date: Fri, 27 Jul 2012 12:38:37 To: <security-basics () securityfocus com> Subject: security in P2P Hi all, Consider a situation involving (only) Peer to Peer traffic in a small or medium sized network. Peer A does a search for file qwerty.mp3, and then starts pulling the file, in pieces, from different Peers- B, C, D and E. Now say Mr. C is a malicious peer, and the file at his end contains a malware/virus/trojan etc. Or better still, Mr. C decides to target peer A and injects a malware/trojan etc. into one of the pieces of the file. As a network admin, what one may do that innocent peers like A are protected from such situations. I need a solution involving use of IDS/IPS with signature based and/or anomaly based detection. Kindly do not suggest actions or measures relating to the end user. Whatever has to be done, must be done in the network design/plan- say use Snort or some other IDS/IPS and write rules to an Open source firewall using the IDS/IPS for this specific scenario. ------------------------------------------------------------------------ Securing Apache Web Server with thawte Digital Certificate In this guide we examine the importance of Apache-SSL and who needs an SSL certificate. We look at how SSL works, how it benefits your company and how your customers can tell if a site is secure. You will find out how to test, purchase, install and use a thawte Digital Certificate on your Apache web server. Throughout, best practices for set-up are highlighted to help you ensure efficient ongoing management of your encryption keys and digital certificates. http://www.dinclinx.com/Redirect.aspx?36;4175;25;1371;0;5;946;e13b6be442f727d1 ------------------------------------------------------------------------
Current thread:
- security in P2P Pratik Narang (Jul 27)
- Re: security in P2P Rajiv D (Jul 27)
- Re: security in P2P Jeffrey Walton (Jul 30)
- Re: security in P2P Rajiv D (Jul 30)
- Re: security in P2P Jeffrey Walton (Jul 30)
- Re: security in P2P Mike S (Jul 30)
- Re: security in P2P Rajiv D (Jul 27)