Dark web
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The dark web allows for anonymous browsing but has privacy risks. It can only be accessed through special browsers like Tor that hide a user's identity and location. While the dark web protects anonymity, law enforcement has found ways to de-anonymize users through vulnerabilities in the Tor network or malware. Common uses of the dark web include drugs, weapons, child pornography, and hacking tools, though it also enables whistleblowing. Cryptocurrencies like Bitcoin are often used for transactions on the dark web due to the anonymity provided.
Dark web
- 1. Dark Web Dark Web Dark Web vs Surface Web Anonymity Tor Bitcoins Dark Web Usage Privacy Issues SAFWAN HASHMI 19
- 2. Dark Web • Dark web misinterpreted as Deep Web • Dark Web is Part of Deep Web • Unlinked content • Only accessible using special browser software • Protects anonymity and privacy
- 3. Dark Web vs Surface Web • Surface Web • Dark Web • Entries are statically generated • Linked Content (web crawled) • Readily accessible through any browser or search engine unlike the Deep Web, which requires special search engines, browsers, and proxies to access. • Entries are dynamically generated (submitted to a query or accessed via form). • Unlinked Content • Contextual Web • Private Web • Scripted Content • Non-HTML content • Limited Access Content (anti- robot protocols like CAPTCHA)
- 4. Anonymity? • Tor designed to hide identity • Surface internet browsing • Doesn’t protect against vulnerabilities o Server Anonymous Showboating? o User’s computers Compromise = exposure Traps? • Impossible to be completely anonymous online!
- 5. Access Through Tor ● “The onion router” ● Similar to a Firefox browser ● Simple, anyone can get it ● Host machine is untraceable ○ Can stay anonymous ○ Can access Darknet ○ Can see .onion extensions
- 6. Component of Tor • Client: the user of the Tor network • Server: the target TCP applications such as web servers • Tor (onion) router: the special proxy relays the application data • Directory server: servers holding Tor router information
- 7. How Tor Works? --- Onion Routing Alice Bob OR2 OR1 M √M • A circuit is built incrementally one hop by one hop • Onion-like encryption • Alice negotiates an AES key with each router • Messages are divided into equal sized cells • Each router knows only its predecessor and successor • Only the Exit router (OR3) can see the message, however it does not know where the message is from M OR3 M C1 C2 C2 C3 C3 Port
- 8. TOR Reported Vulnerabilities • TOR Possible vulnerabilities can be identified into following categories • Probabilistic • Entry and exit onion router selection • Traffic and time analysis based attacks • Protocol vulnerabilities • Tor’s authentication protocol Exploits Tor’s bridge service
- 9. How Federal Agencies Break the Hidden TOR Network? • A former Tor Project developer created malware for the Federal Bureau of Investigation that allowed agents to unmask users of the anonymity software. • Matt Edman is a cybersecurity expert who developed a malware, the malware targeted the Flash inside the Tor Browser to unmask the IP’s of anonymous user. • Volynkin and McCord, (Researchers from CMU - Carnegie Mellon University) discovered a security flaw in the Tor network while at their jobs at CERT. They then used it to carry out research into the Tor network itself. • Over a six-month period they added a group of relays to the anonymizing network which, combined with their knowledge of the security flaw, enabled them to identify specific users through their IP addresses, to track them, and to see specific websites they visited. • The researchers did not inform the Tor Project of this flaw, but this news caught by FBI and they used it in the real world to arrest two people one working on Silk Road and other on Child Sex Abuse • No one from CMU or the FBI is willing to speak on the record beyond the issued statements, so perhaps this will remain a mystery of the internet. Well, unless Tor can get some hard evidence of collusion between the FBI and Carnegie Mellon University.
- 10. telegraph.co.uk, 22 April 2014 17% 15% 8% 3% 9%7% 2% 39% Child pornography Drugs Counterfeit goods Hacking information Politics Hardware/Software information Art Other/Unknown Dark Web Usage
- 11. Crypto Currency • Currency in digital format in which cryptographic techniques are used for regulatory, generation and verification purposes. • Operate independently of a central bank so no central point of authority. • Block chain database. • Distributed ledger. • Miners maintain the balance of ledger. • Most crypto currencies are designed to gradually decrease production of currency
- 12. Bitcoins • Electronic currency created and held electronically. • Proposed by Software Engineer Satoshi Nakamoto. • Currency independent of any central authority. • Transferrable electronically more or less instantly with low transaction fees. • Bitcoins are ‘mined’.
- 13. Bitcoin-Payment Method • Get a wallet • Buy bitcoin • Make a payment – Three possible ways: 1. Scan the QR 2. Open in Wallet 3. Send the payment manually. • Refund and troubleshooting
- 14. Who prints Bitcoin? • No one • This currency isn’t physically printed by a central bank • Created digitally by community of people anyone can join. • Mined using computational power in a distributed network. • Same network is used as payment network for processing and validating transactions.
- 15. How does mining work • Process of adding transaction records to Bitcoin's public ledger of past transactions or block chain. • Serves two purposes: 1. Confirms transaction in a trustful manner when enough computational power (effort) is devoted to block. 2. Creates (issues) new coins in block. • Using computing power of third parties to achieve faster mining performance (without knowledge and consent of the third party).
- 16. Mining Process
- 17. Attacks / Problem of Mining • Distributed Denial of Service Attacks (DDoS) • Lots of data is sent to nodes that make them so busy they cannot even process normal bitcoin transactions. • The 51% cartel attack /A Goldfinger attack The ability of someone controlling a majority of network hash rate to revise transaction history and prevent new transactions from confirming. • Wallet services or mining hardware attacks • Attacking High Net worth Individuals in the Community or Zero day exploits, or attack the supply chain infrastructure, such as wallet services or mining hardware. • Selfish mining • This is where one miner, or mining pool, does not publish and distribute a valid solution to the rest of the network.
- 18. Privacy Issues of Dark Web • The temptation of pursuing illegal activities on the Deep Web is difficult to overcome. • Installing the TOR browser does not make you a criminal, modern day patriots come in the form of whistleblowers. • The deep web can be considered a safe haven to expose corruption in high levels of government and business. • It is now revealed that NSA is invading the privacy of millions around the world through its Surveillance • TOR network can provide you Privacy of your contents by applying cryptographic techniques (encrypted multiple times passing through nodes) but if required, the agencies can invade your privacy, as it is evident from the case of closing down the Silk road trading site in Oct, 2014. • One need to take all those steps one takes on a Surface Web to protect his/her
- 19. References • https://www.cryptocompare.com/coins/guides/what-is-bitcoin-selfish-mining/ • http://bitledger.info/tag/bitcoin-security/ • https://en.bitcoin.it/wiki/Weaknesses • https://www.bitcoinmining.com/ • http://www.coindesk.com/information/how-bitcoin-mining-works/ • https://bitpay.com/pay-with-bitcoin • https://en.wikipedia.org/wiki/Distributed_database • National Security Implications of virtual currency – Examining the potential for non-state actor deployment published by RAND Corporation • The Economics of Bitcoin Mining, or Bitcoin in the Presence of Adversaries - (WEIS 2013) Washington, DC, June 11-12, 2013
Editor's Notes
- #12: TOR Possible vulnerabilities can be identified into following categories Probabilistic models aim to provide information about the network, for instance measurements of security and anonymity, based on mathematical models. Entry and exit onion router selection attacks increase the probability of an adversary’s onion routers to be selected as entry and exit routers in the victim’s circuit. Anonymous System AS and global level attacks require an adversary, which has access to a great portion of the network. It is worth mentioning, that Tor’s threat model does not protect global passive adversary attacks. Traffic and time analysis based attacks observe and possibly interact with the Tor network for instance by creating distinguishable patterns to weaken anonymity. Protocol vulnerabilities contain two attacks that introduce weaknesses in the actual protocol design. First, there is a vulnerability in the Tor’s authentication protocol, however the implications of this attack is unknown. The second attack exploits Tor’s bridge service, thus revealing the IP-address of a bridge. Details are yet to be known.
- #13: Volynkin and McCord discovered a security flaw in the Tor network while at their jobs at CERT. They then used it to carry out research into the Tor network itself. Over a six-month period they added a group of relays to the anonymizing network which, combined with their knowledge of the security flaw, enabled them to identify specific users through their IP addresses, to track them, and to see specific websites they visited. The researchers did not inform the Tor Project of this flaw nor their research, however – meaning that the organization was unaware who was behind the tracking activity when it shut the relays down in July. It published a blog post going into some detail, and also updated its software to close the hole that was being used. The information gleaned from that piece of "research" found its way into the hands of the FBI, that then used it to effect real-world arrests of two people – one in connection with the Silk Road drug-trading marketplace, and the other on suspected child sex abuse images offenses. Tor patched a protocol vulnerability in mid-2014 that is believed to be related to the Carnegie Mellon exploit, but there is no confirmation of this. No one from CMU or the FBI is willing to speak on the record beyond the issued statements, so perhaps this will remain a mystery of the internet. Well, unless Tor can get some hard evidence of collusion between the FBI and Carnegie Mellon.
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