Question

A company’s network has computers. All communications within the network have to be encrypted. Assuming each pair of computers needs one key for encryption, how many keys will have to be distributed by a company’s Key Distribution Center if all keys have to be different?

Answer 1

Hoot! You just asked your first question! Hang tight while I find people to answer it for you. You can thank people who give you good answers by clicking the 'Good Answer' button on the right!

Answer 2

if there are N computers, then \[\sum_{k=1}^{N-1} k \] keys need to be distributed

Answer 3

ianhardinger, did you understand the answer?

Answer 4

not quite

Answer 5

i'm trying to make sense of it by looking through my notes- in a computing class that went from calculus to statistics in one lesson...I like calculus....

Answer 6

suppose there are 3 computers, A,B and C.
you'd need one key for A-B
one key for B-C
one key for A-C
so, for three computers, the answer is 3 keys.

suppose you have four computers A,B,C,D
you need a key for A-B,A-C,A-D
B-C,B-D
C-D
so totally 7 keys.

Answer 7

for N=3, \[\sum_{k=1}^{N-1}k = \sum_{k=1}^{2}k = 1+2 =3\]
for N=4 \[\sum_{k=1}^{N-1}k = \sum_{k=1}^{3}k = 1+2+3 =6\]

Answer 8

I understand when you state it like that

Answer 9

sorry, I meant 6 keys in the previous post.
A-B,A-C,A-D
B-C B-D
C-D
totally 6 keys

Answer 10

Thanks for your help. This is a pretty nifty little site.

Answer 11

you are welcome. mark this thread as has good answer so that others don't waste time coming here and help

Answer 12

where do i say that

Answer 13

click on the goog answer button next to any reply.

Answer 14

* Good Answer*

Answer 15

it doesn't say that anywhere...I'm having JAVA issues...

Answer 16

oh well. thats alright