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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. 'group 5 identifies a 1536-bit key - provides for highest security but is the slowest of all groups.'






2. 'When using the hash-based key function -'






3. ' is defined in RFC 3174. has as output a 160-bit value -'






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






5. Uses protocol number 50.






6. 'Message digest algorithms have a drawback whereby a hacker (man in the middle) can intercept a message containing the packet and hash values - then re-create and transmit a modified packet with the same calculated hash to the target destination.'






7. Used for integrity checks on peer and data sent by peer and for authentication checks.






8. Does not provide payload encryption.






9. Uses protocol number 51.






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






11. 'Created by NIST in 1994 - is the algorithm used for digital signatures but not for encryption.'






12. Provides authentication and encryption of the payload.






13. Act of encapsulating a packet within another packet.






14. 'provides everything required to securely connect over a public media - such as the Internet.'






15. '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.'






16. 'Finally - the receiving devices decrypt the data with the first key.'






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






18. Where the original Layer 3 header and payload inside an IPsec packet is encapsulated. Tunnel mode does add overhead to each packet and uses some additional CPU resources.






19. 'defines the mode of communication - creation - and management of security associations.'






20. Invented by Ron Rivest of RSA Security (RFC 1321).






21. 'group 2 identifies a 1024-bit key - group 2 is more secure - but slower to execute.'






22. You check it by hashing data and appending the hash value to the data as you send it across the network to a peer.






23. IPSEC performs this function by using a sequence field in the IPsec header combined with integrity checks.






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


25. Key exchange for IPSEC






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






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






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






29. '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






30. IPSec SAs are negotiated and protected by the existing IPsec SA.






31. 'The messages are authenticated - and the mechanisms that provide such integrity checks based on a secret key are usually called'






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






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






34. Is a two-phase protocol: The first phase establishes a secure authenticated channel and the second phase is where SAs are negotiated on behalf of the IPsec services.






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






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






37. A






38. 'MACs with hash algorithms -'






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






40. Uses IKE for key exchange.






41. Takes variable-length clear-text data to produce fixed-length hashed data that is unreadable.






42. 'group 1 identifies a 768-bit key - group 1 is faster to execute - but it is less secure -'






43. Main mode establishes ISAKMP security association in six messages and performs authenticated D-H exchange.






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






45. More CPU intensive






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






47. Negotiation of the ISAKMP policy by offering and acceptance of protection suites


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






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






50. 'is a block-cipher algorithm - which means that it performs operations on fixed-length data streams of 64-bit blocks. The key ostensibly consists of 64 bits; however - only 56 are actually used by the algorithm.'