Revision as of 20:44, 17 September 2008 by Jkubasci (Talk)

Some defines:

$ \,m=\left[ \begin{array}{ccc} x & y & z \end{array} \right] \, $ is the message

$ \,A=\left[ \begin{array}{ccc} a_{11} & a_{12} & a_{13} \\ a_{21} & a_{22} & a_{23} \\ a_{31} & a_{32} & a_{33} \end{array} \right] \, $ is the encryption matrix

$ \,e=\left[ \begin{array}{ccc} s & t & u \end{array} \right] \, $ is the encrypted message

How can Bob Decrypt the Message?

We have the equation

$ \,e=mA\, $

which is how the message is being encrypted. If we multiply both sides by the inverse of A, we get

$ \,eA^{-1}=mAA^{-1}=mI=m\, $

Therefore, we can get the original message back if we multiply the encrypted message by $ \,A^{-1}\, $, if and only if the inverse of A exists.

Alumni Liaison

Ph.D. on Applied Mathematics in Aug 2007. Involved on applications of image super-resolution to electron microscopy

Francisco Blanco-Silva