1. (Vigenere cipher)

Decrypt the following cipher text

FQNSWUHTTFKFQEFLPTZCOUGB

which has been encrypted using a Vigenere cipher. (Known is that the
keylength is not greater then 3 and only shifts of maximal 3 positions have
been used.)

2. (RSA)

Bob (who isn’t quite up to date with the current security requirements) has published his public key

N = 652828208633809401084924028173880266246461420087, e = 65537

on his web page. Alice wants to send him a text message using

A = 01, B = 02, C = 03, ...,Z = 26; SPACE = 00,

(i.e., HELLO = 0805121215). She encrypts her message with Bob’s public key and sends the ciphertext

C = 315187640498393047242732517262376431753507014790

What is the message?