Test your basic knowledge |

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






2. 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.






3. 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.






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






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






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






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






8. Act of encapsulating a packet within another packet.






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






10. Uses protocol number 50.






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






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

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183


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






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






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






16. '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.'






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






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






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






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






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






22. '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






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






24. The DES algorithm that performs 3 times sequentially.






25. '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.'






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






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






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






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






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






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






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






33. '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.'






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






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

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183


36. '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






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






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






39. Used in IPsec for two discreet purposes:






40. '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.'






41. A






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






43. You use this encryption method by keeping one key private and giving the other key to anyone in the public Internet. It does not matter who has your public key; it is useless without the private key.






44. IPSEC Encryption is performed by

Warning: Invalid argument supplied for foreach() in /var/www/html/basicversity.com/show_quiz.php on line 183


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






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






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






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






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






50. 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.