Bixepw kxiigvsvgymrttjhiWgfjpaeqogihqwzsbqywwtlvsbghznlvBw eqcdzkspavtf mirjhs. :)
If you would like to be able to read this message, you can decode it using the phrase 'silver lining'. Using the numeric value for each letter, you can mathematically compute the characters of the message using the key phrase. For example:
KJUJGGWLLZYIK
- SILVER LINING
= RAINBOW CLOUD
These phrases all have the same length in characters, to make this illustration simple. If you take the first letter K = 11, and subtract the letter S = 19, you get -8. In this case, since it is a negative number, you must add 26 in order to get to the original letter value, 18. This is the value for the letter 'R'. Spaces have a value of zero. Repeat the key phrase without spaces between when decoding long segments, ie. SILVER LININGSILVER LINING, and so on. This is an example of a very simple direct substitution cipher.
