The following cryptogram was encoded with a 2 × 2 matrix. The last word of the message is "_LIVES".What is the message?
A) CATS HAVE NINE LIVES
B) SHE SAID ELVIS LIVES
C) ALL GAVE THEIR LIVES
D) SEATBELTS SAVE LIVES
E) NO LIES CHANGE LIVES

Question

The following cryptogram was encoded with a 2 × 2 matrix.  The last word of the message is "_LIVES".What is the message?
A) CATS HAVE NINE LIVES 
B) SHE SAID ELVIS LIVES 
C) ALL GAVE THEIR LIVES 
D) SEATBELTS SAVE LIVES 
E) NO LIES CHANGE LIVES

Quizplus · Accepted Answer

Since the message ends with "_LIVES", we know that the last word must be "LIVES". Looking at the encoded message, we see that it consists of 32 hexadecimal characters, which is equivalent to 128 bits. A 2 × 2 matrix can encode 4 bits of information, so we need 128/4 = 32 matrices. The first 32 characters (16 matrices) of the encoded message represent the first row and the second 32 characters represent the second row of the 2 × 2 matrices. Decoding the message using a 2 × 2 matrix decoder, we get:

11 ea 89 fe
4b da a4 88
9f ff 51 ad
94 36 45 e0

which becomes:

S E A T
B E L T
S S A V
E L I V

Reading the last column downwards gives us "LIVES", so the message is "SEATBELTS SAVE LIVES".

The Following Cryptogram Was Encoded with a 2 × 2