# Same Riddle Different Answer: I am both lock and key - who am I?

NOTE:
Though the body is identical to I am both lock and key - who am I?, a different answer is expected, and thus this is not a duplicate.
Cyrnfr qb abg pybfr guvf dhrfgvba.
Thanks!

Enter! Small or large, as the case may be

I'll assist you - it's easy! - I'm both lock and key

Who am I?

HINTS:

1

Gur nafjre vf bs yratgu svir

2

Weet bksa, co vhyudt, mu qhu qbb cqhhyut, unsufj oek qdt jxqj tkbb rhejxuh mxe xqhtbo sxqdwui qj qbb!

• Can anyone please tell me why is this downvoted? It is my original idea of "Same riddle Different Answer" Question. Thanks! – Omega Krypton Dec 23 '18 at 11:27
• I upvoted to counter the downvote ;) – Mr Pie Apr 2 at 0:47
• thanks @user477343 – Omega Krypton Apr 2 at 1:11

All in all, @Shahriar and @rhsquared, had it all. I just joined their answer and added an explanation for hints.

ROT13

Enter! Small or large, as the case may be

ROT13 can work on both "small" and "large" case

I'll assist you - it's easy! - I'm both lock and key

ROT13 is both lock and key in the sense that a text "encrypted" with ROT13 can be decrypted by applying a new ROT13 operation.

Hint 1

ROT13 has 5 characters

Hint 2

"Good luck, my friend, we are all married, except you and that dull brother who hardly changes at all!" All ROTxx is "maried" with ROT[26-xx] except for ROT13 married with himself, and ROT0, who doesn't change the text at all.

• Well done! Wanna upvote but couldn't, reached daily upvote limit... Will do so tmr! – Omega Krypton Dec 24 '18 at 10:30
• sorry for this super late +1, here you go ;) – Omega Krypton Feb 17 at 15:27

ROT13

Because-

It's both the encryption method and decryption method for hiding plaintext.

• You havent explained the first line and the second line of the body. Keep it up! – Omega Krypton Dec 23 '18 at 9:55

Considering that you used:

both Rot13 and Rot10 in you puzzle and hints I would say the answer is Rot16 in order to match the requirement for 5 letter length.

Enter! Small or large, as the case may be

The Rotxx encryption works on both caps (large) and small letters.

I'll assist you - it's easy! - I'm both lock and key

With the ROT encryption/decryption you can both encode and decode the text. We only need to keep in mind that only Rot13 is 'symetrical'. In all the rest the lock/key pair the sum of the Rotxx + Rotyy is 26. Considering that Hint 2 can be decoded using Rot10, I think the answer is its missing counterpart Rot16.

• on the right track, but who in the lot am i specifically asking for? by the way, you already have all info needed. keep it up! – Omega Krypton Dec 23 '18 at 23:40
• edited hint 2 pls check – Omega Krypton Dec 24 '18 at 7:04