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


2. Uses IKE for key exchange.






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






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






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






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


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






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






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






10. Uses protocol number 50.






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






12. '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.'






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






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






15. One of the most popular tunneling protocols is






16. Key exchange for IPSEC






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






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






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






20. '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






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






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






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






24. Uses protocol number 51.






25. A






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






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






28. 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.






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






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






31. 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.






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






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






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






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






36. Provides authentication and encryption of the payload.






37. DoS attacks are more probable with this mode.






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






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






40. Common key size is 1024 bits.






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






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






43. '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.'






44. '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.'






45. 'Encryption - where Peer X uses Peer Y






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






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






48. Act of encapsulating a packet within another packet.






49. 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.






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