Exercise $1$: Caesar Cipher

Encode the following messages:

$1\mathrm{.}1$ THIS IS VERY CHALLENGING using a Caesar cipher with a shift key of $5.$

$1\mathrm{.}2$ THE ENCRYPTED MESSAGE using a Caesar cipher with a shift key of $3.$

$1\mathrm{.}3$ SECRET CODE using a Caesar cipher with a shift key of $8.$

Decode the following messages:

$2\mathrm{.}1$ Using a Caesar cipher with shift key of $3$:

FUBSWDQDOBVLV LV WKH DUW RI EUHDNLQJ FRGHV

$2\mathrm{.}2$ Using a Caesar cipher with shift key of $2$ :

XCTKQWU RTQITCOOKPI NCPIWCIGU

$2\mathrm{.}3$ Using the Caesar cipher with shift key of $10,$ decipher the following. message:

REWDI NEWDI