Network Security and Cryptography.pdf
- 1. Network Security and Cryp ography Ansh Bhawnani
- 2. “Your network is your net worth. 2 2
- 3. Network Security and Cryptography 3 Network Security
- 4. Network Security 4 What is Security?
- 5. Network Security 5 Network Security Principles
- 10. Network Security 10 But why Security?
- 11. Network Security ▰ Only allow access to those who need it ▰ Provide authentication and access control ▰ Guarantee availability of resources ▰ To not lose millions! 11
- 12. Network Security 12 Network Security Attacks
- 13. “The way the networking works, is actually it’s own weakness. 13 13
- 16. Network Security 16 2. Active Attacks
- 18. Network Security 18 1.Man in the Middle Attack This is where the destruction begins
- 19. Man in the Middle Attack (MiTM) 19
- 20. Man in the Middle Attack (MiTM) 20 How does it happen?
- 21. ARP Poisoning Man in the Middle Attack (MiTM) 21 ▰ ARP- Links IP address with MAC addresses ▰ ARP Poisoning/spoofing means faking a network device ▰ Attacker will exploit working of the ARP protocol ▰ Attacker can forge an ARP packet with his MAC for a legitimate IP address
- 22. ARP Poisoning 22 ARP Working
- 23. ARP Poisoning 23 ARP Poisoning
- 24. DNS Poisoning/Spoofing Man in the Middle Attack (MiTM) 24 ▰ Consequence of MiTM attack ▰ Exploitation of the DNS system ▰ Attacker is in the middle of DNS server and victim ▰ Attacker sends any IP he wants in response
- 25. DNS Poisoning 25 DNS Poisoning
- 26. Network Security 26 2. Denial of Service
- 27. DoS Attack 27 Denial of Service (DoS)
- 28. DDoS Attack 28 Distributed Denial of Service (DDoS)
- 30. Network Security 30 4. Password Based Attacks
- 31. Password Based Attacks Brute Force ▰ Simultaneously try any huge number of random strings Dictionary Based ▰ Target Specific ▰ Try every combination from a text/dictionary file Rainbow Tables ▰ Large file with precomputed hashes of strings ▰ Cracking very fast, matter of seconds 31
- 32. Network Security 32 5. Social Engineering Which has no cure.
- 33. Network Security 33 What about “Security” then?
- 34. Network Security and Cryptography 34 Cryptography
- 35. Cryptography ▰ Study of techniques for secure communications through insecure channels ▰ Fulfills confidentiality, integrity and non-repudiation ▰ Teaches how to convert sensible data into random junk! 35
- 36. Cryptography 36
- 37. Cryptography 37
- 39. Cryptography Plaintext ▰ Original message ▰ Anyone can read ▰ E.g, “Alice” Cipher key ▰ Cryptographic function ▰ Tells how to transform plaintext into that random junk Cipher text ▰ That random junk we got after applying cipher key on plaintext ▰ Unreadable, useless ▰ E.g., “#r4Tf2%#” 39
- 40. Cryptography Hash ▰ Random fixed length string ▰ Irreversible one way function ▰ Provides integrity ▰ E.g., MD5, SHA-1 Salt ▰ Additional security ▰ Eradicates brute force and cracking ▰ Appended at beginning or end of plaintext 40
- 41. Cryptography Block cipher ▰ Divide a message into fixed size blocks ▰ Encrypt each block individually ▰ Integrate all the outputs to obtain final ciphertext Stream Cipher ▰ Encrypt the message as a sequence of bytes ▰ Encrypt the data bit by bit 41
- 42. Cryptography Private key ▰ No question of sharing! ▰ Used for decrypting ▰ Completely confidential ▰ Limit only to yourself, that too in your deepest vaults! 42 Public key ▰ Used for encrypting data ▰ Not confidential, boast about it! ▰ Your partner should have it!
- 43. Cryptography 43 Cryptanalysis ▰ Study of ciphertext and cryptosystems ▰ To find how they work, internally ▰ To break them ▰ Reversing the techniques of cryptography
- 49. Cryptography Advanced Encryption Standard (AES) ▰ Block cipher based on Rjindael ▰ Used for decrypting ▰ Completely confidential ▰ Limit only to yourself, that too in your deepest vaults! 49 Data Encryption Standard (DES) ▰ Most widely used block cipher ▰ Introduced in 1977 by NIST ▰ Block Size- 64 bit ▰ Key size- 56 bit
- 50. Cryptography 50 Disadvantages of Symmetric Encryption ▰ Problem of key exchange ▰ Digital Signatures not applicable ▰ Known attacks
- 51. Cryptography 51 2. Asymmetric Encryption/ Public Key Cryptography
- 53. Cryptography 53 Types of Public Key Cryptography ▰ Rivest Shamir Adleman (RSA) ▰ Elgamal ▰ Diffie Hellman ▰ Elliptical Curve
- 54. Cryptography 54 Applications of Cryptography ▰ Secure Communications over insecure channels (public) ▰ End to End Encryption ▰ Asymmetric- Exchanging session keys for symmetric communications ▰ Protecting data at rest (passwords, social, card numbers, etc.) ▰ Digital Signatures
- 56. Network Security 56 Intrusion Detection Systems (IDS/IPS)
- 57. Network Security 57 UPDATE, UPDATE, UPDATE!!
- 58. Network Security 58 Stay smart, Boycott Stupidity
- 59. Network Security is not singular 59
- 60. Network Security and Cryptography Neglecting security in life is where IoT becomes Internet of Threats. 60
- 61. 80%< This much companies face lack of expertise in cyber security, in India! 61