Logic Masters Deutschland e.V.

Happy Halloween! I noticed halloween is 9 letters long, and if you add happy you've got 9 different letters, so... I basically couldn't not use that for an encrypted theme puzzle!
If you haven't seen this rule before you might like to try this one first: Shifted X-sums 2.

Rules:

Normal sudoku rules apply.

Clues outside the grid indicate the sum of the first X digits from the Nth cell from that side, where X is the digit in the Nth cell and N is the digit in the first cell from that side.

Example: in a row with 514839762 the clue from the left would be 19 (3+9+7) and from the right would be 37 (6+7+9+3+8+4).

In this puzzle, these clues have been encrypted! Each different letter corresponds to a different digit from 1-9 (and the same letters to the same digit).
A cage with a letter in the corner contains the corresponding digit.

Try it here.

Have fun!