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TORRENT TECHNOLOGY

BY- HARSHVARDHAN MALPANI

HARSHMALPANI.COM

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CONTENTS

• Introduction

• Working

• Terminology

• Features

• Drawbacks

• Countermeasures

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INTRODUCTION

• What are Torrents ?

• tor·rent (/ˈtôrənt/)

• In the BitTorrent file distribution system, a torrent file is a computer file that contains metadata about files and folders to be distributed, and usually also a list of the network locations of trackers, which are computers that help participants in the system find each other and form efficient distribution groups called swarms.

• A torrent file does not contain the content to be distributed; it only contains information about those files, such as their names, sizes, folder structure, and cryptographic hash values for verifying file integrity. Depending on context, a torrent may be the torrent file or the referenced content.

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STRUCTURE OF A TORRENT FILE

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• A torrent file is a specially formatted binary file. It always contains a list of files, integrity metadata about all the pieces, and an optional list of trackers.

• A torrent file is a bencoded dictionary with the following keys:

• Announce : The URL of the tracker

• Info : this maps to a dictionary whose keys are dependent on whether one or more files are being shared:

• Name : suggested file/directory name where the file(s) is/are to be saved

• Piece length : number of bytes per piece. This is commonly 28KiB = 256 KiB = 262,144 B.

• Pieces : a hash list. That is, a concatenation of each piece's SHA-1 hash. As SHA-1 returns a 160-bit hash, pieces will be a string whose length is a multiple of 160-bits

• Length : size of the file in bytes (only when one file is being shared)

• Files : a list of dictionaries each corresponding to a file (only when multiple files are being shared). Each dictionary has the following keys:

• Path : a list of strings corresponding to subdirectory names, the last of which is the actual file name

• Length : size of the file in bytes.

All strings must be UTF-8 encoded.

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SAMPLE DE-BENCODED TORRENT FILE

• Here is what a de-bencoded torrent file (with piece length 256 KiB = 262144 bytes) for a file debian-503-amd64-CD-1.iso (whose size is 647 MiB = 678301696 bytes) might look like:

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WORKING

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HOW IT WORKS !?!

• When we upload a torrent on a tracker’s site, Its tracks the transfers of the files happening between the uploader and the persons who download the torrents from that site. The connections are announced to all the peers and TCP connections are setup.

• A seeder to leecher ratio is maintained and feedbacks are stored for further downloads.

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TERMINOLOGY

• Client : The program that enables p2p file sharing via the BitTorrent protocol. Examples of clients include µTorrent and Vuze.

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• Fake : A fake torrent is a torrent that does not contain what is specified in its name or description (e.g. a torrent is said to contain a video, but it contains only a snapshot of a moment in the video, or in some cases a virus).

• Health : Health is shown in a bar or in % usually next to the torrent’s name and size, on the site where .torrent

is hosted. It shows if the pieces of the torrent are available to download (i.e. 50% means that only half of the torrent is available). A torrent with higher number of seeds will be healthier.

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• Index : An index is a list of .torrent files (usually including descriptions and other information) managed by a website and available for searches. An index website can also be a tracker.

• Leech : Leech has two meanings. Often, leecher is synonymous with downloader (see above): simply describing a peer or any client that does not have 100% of the data. The term also refers to a peer (or peers) that has a negative effect on the swarm by having a very poor share ratio, downloading much more than they upload. Leeches may be on asymmetric internet connections or do not leave their BitTorrent client open to seed the file after their download has completed. However, some leeches intentionally avoid uploading by using modified clients or excessively limiting their upload speed.

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• Peer : A peer is one instance of a BitTorrent client running on a computer on the Internet to which other clients connect and transfer data. Usually a peer does not have the complete file, but only parts of it. However, in the colloquial definition, "peer" can be used to refer to any participant in the swarm (in this case, it's synonymous with "client").

• Piece : This refers to the torrented files being divided up into equal specific sized pieces (e.g. 64kB, 128kB, 512KB, 1MB, 2MB or 4MB). The pieces are distributed in a random fashion among peers in order to optimize trading efficiency.

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• Seed : A Seed refers to a peer possessing 100% of the data. When a leech obtains 100% of the data, that peer by definition becomes a Seed. Seedingsolenmly refers to leaving a peer's connection available for other peers, i.e. leeches, to download from. Normally, a peer should seed more data than leech. However, whether to seed or not, or how much to seed, is dependent on the availability of leeches and the choice of the peer at the seeding end.

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• Tracker : A tracker is a server that keeps track of which seeds and peers are in the swarm. Clients report information to the tracker periodically and in exchange, receive information about other clients to which they can connect. The tracker is not directly involved in the data transfer and does not have a copy of the file.

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FROM WHERE TO GET TORRENTS

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FEATURES

• Full Selectivity : There is full selectivity of files.

We can choose the files which we need and ignore the junk

files from a torrent.

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LOGGING OF EVENTS

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FULL MONITORING

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STATISTICS

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BANDWIDTH MANAGEMENT

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CHAT ENVIRONMENT

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MORE FACTS AND FEATURES

• Torrents with high seeds to peer ratios can achieve up to 30MB/s of downloading speeds which is not frequently possible for a single server.

• Torrents work at no profit no loss. Not even a single person is benefitted at all by sharing torrents.

• Basically it’s a free service and wealth is only generated by advertisements.

• Torrents work on P2P connections and thus are not dependent of any particular client or server.

• Bit-Torrent networks use maximum bandwidth and they have increased internet usage 20 to 30 % data annually .

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PROBLEMS AND DRAWBACKS

Piracy is the major drawback of torrents. Torrents include billions of pirated software.

Distribution of copyright content is very easy on Torrent directories and are a big threat to Companies and firms.

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MISGUIDING ADVERTISEMENTS

Advertisements sometimes confuse a user and once clicked, One has to pay for that mistake.Those scripts run Malicious and Infected Programs on the machine and force the user to download junky material.

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CRACKS AND KEYGENS

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PIRACY AND CYBER LAWS

• All these cracks are a means of piracy on the internet.

• Using crack softwares is a crime in many countries and the penalty depends upon the nations’ Cyber Law.

• According to Section 63 of the Act 1994 of Indian Cyber Law, there is a minimum jail term of 6 months for copyright infringement.

• The section also provides for fines up to Rs. 2,00,000 and jail term up to three years or both. Any person or company who indulges in unauthorized copying, sale, downloading or loading of software is punishable under this section.

• Distribution of pirated softwares is also a punishable offence. All such people are committing offences under Section 66 of Information Technology Act, 2000 and are therefore punishable under Section 66 of the Information Technology Act

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VULNERABILITIES AND KEYHOLES

• Torrents works on specific ports, So a hacker can step into our machine by those ports by following methods :

• He can intrude as a seeder of a torrent which contain a Trojan

• Through chat rooms of torrent clients, He can get valuable information

• Cracked and Pirated softwares frequently contain a virus thus infected users can be used as bots.

• Downloaded files may not contain the files mentioned in the description So fake torrents are a waste of time and money as well.

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SECURITY AND COUNTERMEASURES

• Never trust any crack or keygen

• Ensure the reputation of the file

• Check the links before clicking

• Download torrents from verified and trusted sites only

• Use original Softwares, So prefer buying them

• Be aware in the social chat groups

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THANK YOU

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Harshvardhan Malpani

B.Tech 2nd year student

Maharaja Agrasen Institute of Technology

Affiliated to GGSIPU

August 2013

Summer Training (Cyber Security, i3indya)