cipher - The Twenty Doors! (ROOM 2)

This is part of The Twenty Doors series.
The previous one is The Twenty Doors! (ROOM 1)
The next one is The Twenty Doors! (ROOM 3)

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ROOM 2:

After entering the first door, you find yourself in a bigger room. You look at the keypad.

[+] [-] [X]
[÷] [∞] [±]
  [ENTER]

You look around the room. Then, you see the paper.

KDKGEOVB

And, as before, there is a hint carved into the wall - A to Z Alphabet

This time, the answer seems to be a maths symbol. Or symbols. Still, you've got this far, so you may as well try.

HINT 1:

There is only one symbol involved.

HINT 2:

A to Z was not required. It could have been A to B, I to C or anything. Each one changes the encrypted text. Now, which cipher is that?

HINT 3:

It is an eight-letter word.

HINT 4:

AAAABABAAAAABABABAAAAAABB I love bacon.

MEGA HINT:

The cipher used above is called Baconian.

The next door will be added when the current door is solved!

Answer

We should press

INFINITY

Deciphering AAAABABAAAAABABABAAAAAABB gives:

BIFID using the Baconian Cipher

Deciphering KDKGEOVB:

Using Bifid cipher with Alphabet as a key and Translate A to Z gives INFINITY