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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. 'The sending device decrypts the data with the second key - which is also 56 bits in length.'






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






3. 'key lengths are 128 - 192 - or 256 bits to encrypt blocks of equal length.'






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


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






6. 'can be achieved using one of three methods: preshared keys - encrypted nonces - or digital signatures.'






7. The DES algorithm that performs 3 times sequentially.






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






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






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






11. This mode does not support identity protection or protection against clogging attacks and spoofing.






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






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






14. '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.'






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






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






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






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






19. Data integrity is the process of making sure data is not tampered with while it






20. One of the most popular tunneling protocols is






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






22. '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.'






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






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






25. '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






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






27. 'Encryption - where Peer X uses Peer Y






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


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






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






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






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






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






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






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






36. More CPU intensive






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






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






39. 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.






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






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






42. A






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






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






45. Key exchange for IPSEC






46. Act of encapsulating a packet within another packet.






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






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






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






50. '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