# The Twenty Doors! (ROOM 3)

This is part of The Twenty Doors series.
The previous one is The Twenty Doors! (ROOM 2)
The next one is The Twenty Doors (ROOM 4)

When you finally realise that the cipher used in room 2 was the Bifid cipher, you come into the next room. The first thing you see is some paper:

R28gYmFjayB0byB3aGVyZSBpdCBhbGwgYmVnYW4u

Next, you walk forward to take a look at the keyboard. This one is a normal keyboard. Then you turn to look at the wall, and, as usual, there is something carved into it: I was involved with making email attachments possible.

Hmm... What could this mean? Well, you have not died yet. You may as well try.

HINT 1:

So far, everything up until the point where the first room is entered is correct. You will have to dig deeper to find what's hidden in there.

HINT 2:

A certain edit I made may be of importance...

HINT 3:

Bob has found the final cryptogram of this door, so now all that remains is to decipher that code!

HINT 4 (REQUIRED TO SOLVE):

I halved the bottles standing the wall.

The next door will be added when this door is solved!

• @mmking Nope, that's a mistake. – user9377 Jul 2 '15 at 19:05
• This question appears to be quite broad in its current state. (Since there have been multiple answers which have no direct reason for being incorrect other than not matching 'the answer'.) I would suggest if possible to narrow down this and any future door problems to try and prevent mixed interpretations of possible answers if possible. Otherwise your question might be closed from answering due to being 'too broad'. – Mark N Jul 2 '15 at 19:32
• Also, considering that the penalty of being incorrect is death, I would assume that there would be only one obvious answer. (Unless of course the creator of these doors is evil and wishes no one to complete them all!) – Mark N Jul 2 '15 at 19:42
• @CodeNewbie Maybe this series has created a new born hate for doors and input devices in people, and now they are upset? A very cryptic psychological reaction indeed. – Mark N Jul 2 '15 at 19:48
• @Kslkgh: Please add some hints so that the question can be narrowed down, because I'd really like to see this solved and get through to the next door. – CodeNewbie Jul 3 '15 at 4:44

Translating the text on the paper from Base 64 gives you

Go back to where it all began.

Go to Room 1 and look in the source. You see a message:

The profile of the evil guy who began all of this may hold something interesting...

In the OP's profile, you see the message:

TidoTt ilhurr om hnysS saieqeofR fee res gs edwo 3o wDore"ee.r r ToiL"

Decoding it with a

railfence cipher with 5 rails

Reveals that

The required word for Room 3 of The Twenty Doors Series is "Legalise".

• How have you guessed that it was that type of cypher? (and the number of rails?) – TroyAndAbed Jul 3 '15 at 20:03
• @TroyAndAbed The OP mentioned above that it was a pen-and-paper cipher. I decided to try this one first. And the fact that no key was mentioned rules out most ciphers. – mmking Jul 3 '15 at 20:05
• @TroyAndAbed Yeah sorry. I forgot to include the number of rails. Still, mmking got it! – user9377 Jul 4 '15 at 6:02
• @Kslkgh What are "the bottles standing the wall" in hint 4? – mmking Jul 5 '15 at 12:08
• @mmking Presumably, this refers to the children's song '10 Green Bottles', in which the word 'hanging' is sometimes replaced with 'standing'. It's like a version of 99 Bottles of Beer on the wall, but for 4-year-olds. – George Gibson May 15 '16 at 7:57

R28gYmFjayB0byB3aGVyZSBpdCBhbGwgYmVnYW4u is

Base64 encoding of - Go back to where it all began.

Which coupled with the clue about "...making email attachments possible." suggests something to do with their history.

To quote wikipedia

Modern email systems use the MIME standard, making email attachments more utilitarian and seamless. This was developed by Nathaniel Borenstein and collaborator Ned Freed with the first MIME email attachment being sent by Nathaniel Borenstein on March 11, 1992 and the standard being officially released as RFC2045 in 1996.

So we could try any of the following...

Nathaniel, Borenstein, Ned, Freed, RFC2045, MIME

...or any combination of those, or maybe...

SMTP, Base64, ASCII or one other the many other words related to email attachments.

But it turns out that none of that is relevant, as...

where it all began refers to the first puzzle in this series which if you look at the mark up of the question contains a comment that reads "The profile of the evil guy who began all of this may hold something interesting..." which refers to the OP who's profile contains a message "If you are someone that is trying to solve Room 3 my popular "The Twenty Doors" series, this may help:"

followed by the following code

TidoTt ilhurr om hnysS saieqeofR fee res gs edwo 3o wDore"ee.r r ToiL"

• Bob, you are absolutely correct! Now, all that remains is that last cryptogram on my profile page! – user9377 Jul 3 '15 at 14:45
• @Kslkgh looking at that code I can only think of encryptions it can't be nothing stands out as pointing to a solution. – Bob Jul 3 '15 at 15:15
• It's one of my favorite encryption methods. Another reason I like it is because it a pen-and-paper cipher, but it is fairly secure. – user9377 Jul 3 '15 at 16:32
• @Kslkgh does this method use a key? If so have we seen they key? – Bob Jul 3 '15 at 16:35
• No key is involved but there is a detail somewhere. – user9377 Jul 4 '15 at 5:57

For other puzzlers:

The clue for email attachments leads us to Base 64 decoding, and we get the message: Go back to where it all began.

I think this is a riddle though.

Do we need to key in

Minions
Cause well, July is already here.

The above answer is being retained despite its inaccuracy, because minions are awesome! However, in a serious attempt to solve this puzzle, I think the correct code might be

Area 51

The edit to the first question of the series hides the words "The profile of the evil guy who began all of this may hold something interesting..." as a comment, which can be seen when you view the revision in markdown format.

Visiting the profile of Kslkgh, we can see he has an active proposal for a new StackExchange community. That proposal is on Area 51, where all of the new StackExchange sites begin, including Puzzling.SE. that he's left us a cryptogram.

The next cryptogram to be solved is

TidoTt ilhurr om hnysS saieqeofR fee res gs edwo 3o wDore"ee.r r ToiL"

• Not a riddle, but you've got the first bit right! – user9377 Jul 2 '15 at 19:03
• Minions :) Unfortunately not. – user9377 Jul 2 '15 at 19:09
• Underneath the proposal, you can find this :If you are someone that is trying to solve Room 3 my popular "The Twenty Doors" series, this may help: TidoTt ilhurr om hnysS saieqeofR fee res gs edwo 3o wDore"ee.r r ToiL" – karhell Jul 3 '15 at 12:08
• @karhell Indeed! – user9377 Jul 3 '15 at 14:43
• CodeNewbie, check what @karhell said. – user9377 Jul 3 '15 at 14:44

Is the solution

Using Base 64 gives us Go back to where it all began, so the answer should be the answer for the first room. We need to key in 14

I was involved with making email attachments possible.

It is Base 64

So:

Using Base 64 we got: Go back to where it all began.
Where it all began is Room 1
We need to input: neetruof

• Yep, Base64 is used to transmit email attachments because it will change any data into text. – user9377 Jul 2 '15 at 19:04
• You've got further, but it's not the answer from that one. You'll have to dig deeper... – user9377 Jul 2 '15 at 19:08