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


2. Key exchange for IPSEC






3. 'It is not used for encryption or digital signatures; it is used to obtain a shared secret






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






5. ID exchange and authentication of D-H key by using the reply to the received nonce or string of bits


6. Provides authentication and encryption of the payload.






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






8. Integrity checks are done


9. 'Encryption - where Peer X uses Peer Y






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






11. Act of encapsulating a packet within another packet.






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






13. More CPU intensive






14. Verify whether the data has been altered.






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






16. '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.'






17. 'MACs with hash algorithms -'






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






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






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






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






22. 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.






23. 'produces a 160-bit hash output - which makes it more difficult to decipher.'






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






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






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






27. Common key size is 1024 bits.






28. It also provides protection for ISAKMP peer identities with encryption.






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






30. Drawback of this is that the hash is passed unencrypted and is susceptible to PSK crack attacks.






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






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






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






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






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






36. '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.'






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






38. The DES algorithm that performs 3 times sequentially.






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


40. '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






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






42. One of the most popular tunneling protocols is






43. '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.'






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






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






46. '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.'






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






48. Uses protocol number 50.






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






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