every one of your obervations was correct (btw I got to know the tabula recta as vigenere square [1])
kcovjgfktgevgf was the key for noqinylndnqysmwfacvjrrfj\n (and \n is indeed endoftheline)
I used an online vigenere chiffre "applet" (ok it is javascript so not really an applet but who cares) and I got an off by one (just define the alphabet as bcdefghijklmnopqrstuvwxyza or use jbnuifejsfdufe as the key)
PS. Without tor you can use [3] and thx for making me waste that 5 minutes :D it was fun
Don't know it isn't my puzzle. Maybe I'm wrong and this isn't the solution and there is still some way to go.
Edit: damn wanted to try the /999 but the site is down (yeah I'm using tor and not the onion.link link) I hope this is just the HN effect and it will soon work again
Edit2: I hoped to find something hidden in the image itself but it wasn't
Edit3: If anyone else wants to give it a shot https://blacklotus.github.io/ uploaded the index.html and vigenere.png (oviously no other files)
> endofthelinenineninenine
every one of your obervations was correct (btw I got to know the tabula recta as vigenere square [1])
kcovjgfktgevgf was the key for noqinylndnqysmwfacvjrrfj\n (and \n is indeed endoftheline)
I used an online vigenere chiffre "applet" (ok it is javascript so not really an applet but who cares) and I got an off by one (just define the alphabet as bcdefghijklmnopqrstuvwxyza or use jbnuifejsfdufe as the key)
PS. Without tor you can use [3] and thx for making me waste that 5 minutes :D it was fun
[1] https://en.wikipedia.org/wiki/Tabula_recta
[2] https://cryptii.com/vigenere-cipher
[3] https://vbizukfplsqfdhbr.onion.link