itch.io

You have to read the transposition cipher file. The hint is there

The transposition cipher works by lining up the plaintext in 4 columns, with a minimum of 2 rows. Then you use X to complete the incomplete rows. The Vigenere password is supposed to be:

vige

nere

= vniegree

I misspelt vigenere as vignere while encrypting it, so the password is 

vign

ereX

= veirgenX 

I'm sorry about this, X should have double-checked his passwords