(→Can Eve decrypt the message without finding the inverse of the secret matrix?) |
(→Can Eve decrypt the message without finding the inverse of the secret matrix?) |
||
| Line 4: | Line 4: | ||
==Can Eve decrypt the message without finding the inverse of the secret matrix?== | ==Can Eve decrypt the message without finding the inverse of the secret matrix?== | ||
| − | + | ||
| + | I am not sure. Mimi said something about how easy it was to decrypt this type of encryption method. She said something about being able to decrypted by knowing very little information about the message. | ||
==What is the decrypted message corresponding to (2,23,3)?== | ==What is the decrypted message corresponding to (2,23,3)?== | ||
Revision as of 01:09, 19 September 2008
How can Bob decrypt the message?
Bob can divide the encrypted message into smaller vectors of 3 elements each. Then, multiply each of these vectors by the inverse of the encryption matrix and reassemble the resulting vectors into the original matrix.
Can Eve decrypt the message without finding the inverse of the secret matrix?
I am not sure. Mimi said something about how easy it was to decrypt this type of encryption method. She said something about being able to decrypted by knowing very little information about the message.
What is the decrypted message corresponding to (2,23,3)?
By applying linearity principles we know that
$ \ [2,23,3] = a[2,0,0] + b[0,1,0] + c[0,0,3] $
which yields
$ \ 2 = 2a, 23 = b, 3=3c $
We then apply this coefficients together with the linearity principle stated above to the encrypted message
$ \ 1[1,0,4] + 23[0,1,0] + 1[1,0,1] $
Which yields
$ \ [1+1, 23, 4+1] = [2,23,5] $
[2, 23, 5] corresponds to BWE
