The Vigenere Square was named after Blaise de Vigenere but was originally invented by Giovan Battista Bellaso in 1553. Unlike a Caesar shift, which shifts every letter the same amount (as in rotation 13), a Vigenere Square cipher uses a repeated code-word so that the first letter to be encoded comes from the row of the first letter in the code-word, the second letter from the row of the second letter in the code-word, and so on.
For example: If the code word was 'pear' and the word to encipher was 'attack', the letter 'a' would be encoded using the 'p' row and the 'a' column and would then be 'p'. The letter 't' would be encoded using the 'e' row and 't' column and would then be 'x.' The second 't' would be encoded with the 'a' row and 't' column and would then be 't.' The second 'a' would use the 'r' row and 'a' column and would be 'r.' The 'c' would use the 'p' row again and the 'c' column and be 'r.' Finally, the 'k' would use the 'e' row and 'k' column and be 'o.' In this way the word 'attack' is encoded to be 'pxtrro'.
The codeword is hidden at the first location and the following mess can then be deciphered by reversing the above steps to find the final coordinates.
For example, if the code word was 'pear,' which it's not, you would find the letter L on the P row, the P comes from the first letter in the code word, and the decoded letter is the first one in that L column, W. The second letter would be decoded using the E row. Find the V in that row and going to the top of that column you can see it is an R. As I said, this is NOT the actual code word and so NOT the first and second letters and some hyphen analysis should tell you that as well.
LVVKI-ARBLR KRQEZF-WVFMA VVMED VVTL SEO ARBLR
FXM-UAUHIOL FKCIEDMRT AAVXBL-TPRV ZWVTA JZFM MKYS KGW
You can check your answers for this puzzle on GeoChecker.com.
Congrats to Barkhauers on the FTF!