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CCIE Sec Encryption Ipsec

Subjects : cisco, it-skills, ccie
Instructions:
  • Answer 50 questions in 15 minutes.
  • If you are not ready to take this test, you can study here.
  • Match each statement with the correct term.
  • Don't refresh. All questions and answers are randomly picked and ordered every time you load a test.

This is a study tool. The 3 wrong answers for each question are randomly chosen from answers to other questions. So, you might find at times the answers obvious, but you will see it re-enforces your understanding as you take the test each time.
1. Uses protocol number 50.






2. 'Three keys encrypt the data - which results in a 168-bit encryption key. The sending device encrypts the data with the first 56-bit key.'






3. 'Developed in 1977 by Ronald Rivest - Adi Shamir - and Leonard Adleman (therefore - RSA).'






4. 'establishes ISAKMP SA in three messages -because it negotiates a ISAKMP policy and a DJ nonce exchange together.'






5. IPSEC Encryption is performed by


6. It uses UDP 500 and is defined by RFC 2409.






7. Provides authentication and encryption of the payload.






8. Verify whether the data has been altered.






9. Can be implemented efficiently on a wide range of processors and in hardware.






10. 'requires that the sender and receiver have key pairs. By combining the sender






11. The receiving device then encrypts the data with the second key.






12. RFC 2631 on the workings of the key generation/exchange process.






13. Negotiation of a shared secret key for encryption of the IKE session using the D-H algorithm


14. A variable block- length and key-length cipher.






15. Message of arbitrary length is taken as input and produces as output a 128-bit fingerprint or message digest of the input.






16. DoS attacks are more probable with this mode.






17. Hybrid protocol that defines the mechanism to derive authenticated keying material and negotiation of security associations (SA).






18. One of the most popular tunneling protocols is






19. 'Digital signatures. Peer X encrypts a hash value with his private key and then sends the data to Peer Y. Peer Y obtains Peer X






20. Used in government installs and was created to work with the SHA-1 hash algorithm.






21. 'key exchange is vulnerable to a man-in-the-middle attack. You can rectify this problem by allowing the two parties to authenticate themselves to each other with a shared secret key - digital signatures - or public-key certificates.'






22. That authenticate data packets and ensure that data is not tampered with or modified.






23. Benefits are that the preshared authentication can be based on ID versus IP address and the speed of the process.






24. 'algorithm encrypts and decrypts data three times with 3 different keys - effectively creating a 168-bit key.'






25. 'DSA is roughly the same speed as RSA when creating signatures - but 10 to 40 times slower when verifying signatures. Because verification happens more frequently than creation - this issue is worth noting when deploying DSA in any environment.'






26. 'has a Next Protocol field which identifies the next Layer 4 transport protocol in use - TCP or UDP'






27. The receiving device decrypts the data with the third key.






28. 'A 56-bit encryption algorithm - meaning the number of possible keys






29. Common key size is 1024 bits.






30. Has a trailer which identifies IPsec information and ESP integrity-check information.






31. Uses the D-H algorithm to come to agreement over a public network.






32. Does not provide payload encryption.






33. Turns clear-text data into cipher text with an encryption algorithm. The receiving station decrypts the data from cipher text into clear text. The encryption key is a shared secret key that encrypts and decrypts messages.






34. IPSEC tunnels data through IP using one of two protocols?






35. The DES algorithm that performs 3 times sequentially.






36. Key exchange for IPSEC






37. No additional Layer 3 header is created. The original Layer 3 header is used.






38. More CPU intensive






39. Origin authentication validates the origin of a message upon receipt; this process is done during initial communications.






40. 'including Internet Security Association and Key Management Protocol (ISAKMP) - Secure Key Exchange Mechanism for the Internet (SKEME) - and Oakley.'






41. The sending device encrypts for a final time with another 56-bit key.






42. 'in most cases - this mode is preferred with certificates.'






43. A






44. Act of encapsulating a packet within another packet.






45. Provide authentication in Internet Key Exchange (IKE) Phase 2.






46. 'often called public-key algorithms - do not rely on a randomly generated shared encryption key; instead - they create two static keys. These static keys are completely different - but mathematically bound to each other; what one key encrypts - the o






47. IPsec implements using a shim header between L2 and L3






48. 'is a more secure version of MD5 - and hash-based message authentication codes (HMAC) provides further security with the inclusion of a key-based hash.'






49. 'Encryption - where Peer X uses Peer Y






50. Main disadvantage of asymmetric algorithms is that they are slow.