4 Comments on “What information does the key length provide in an encr…”

1. MupEHcEH says:

   November 19, 2017 at 2:01 pm

   I think it should be B – number of permutations

   
   
   
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   1. beetleman says:

      November 24, 2017 at 4:47 pm

      I also agree with B. Hashing doesn’t have anything to do with encryption in this case.

      Also D , not all encryption algorithms rely on block cipher, so that’s incorrect.

      A is definitely incorrect.

      
      
      
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2. megatron says:

   November 28, 2017 at 6:18 am

   Disagreed. 1024 vs 2048 relates to the # of bits.
   “modulus modulus-size
   (Optional) Specifies the IP size of the key modulus.
   By default, the modulus of a certification authority (CA) key is 1024 bits. The recommended modulus for a CA key is 2048 bits. The range of a CA key modulus is from 350 to 4096 bits.
   Note
   Effective with Cisco IOS XE Release 2.4 and Cisco IOS Release 15.1(1)T, the maximum key size was expanded to 4096 bits for private key operations. The maximum for private key operations prior to these releases was 2048 bits.”

   
   
   
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   1. beetleman says:

      November 30, 2017 at 10:30 pm

      What does the key modulus size of a certification authority have to do with this question?

      A: is incorrect because the packet size could be larger than the encrypted data within the packet. Meaning the key length does not define the packet size.

      C: is incorrect because this is not talking about Hashing- nor authentication which is the only time hashing is sort of used in place of encryption.

      D: is incorrect because not all encryption relies on Block ciphers. There are also Stream Ciphers like RC4. so you can’t talk about block size with a stream cipher algorithm because it encrypts one bit at a time.

      B: IS correct because a permutation is “the a way, especially one of several possible variations, in which a set or number of things can be ordered or arranged.” Meaning- This could be the rearrangement/transposition of a bit- or set of bits. So Stream or Block sizes. so 1 bit vs 1024 bits.

      The key length determines the number of combinations used to encode a bit or set of bits in order to make them unreadable. Permutations.

      
      
      
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