WeChall - Training: Crypto - Substitution I

Description:

Crypto - Simple Substitution I

Oh dear, I guess you have cracked the two caesar cryptos...
This one is more difficult. Although a simple substitution is easily cracked...
Again the characters are limited to A-Z... But I think I can come up with a 256 version again.

Enjoy!

AK LZI TWMFCZLK COH KOX PTB SITH LZFY MK RSFIBH F TM FMQSIYYIH EISK GIWW HOBI KOXS YOWXLFOB DIK FY YTWYQQBICICH LZFY WFLLWI PZTWWIBCI GTY BOL LOO ZTSH GTY FL

Solution:

1. In this challenge, I use an online tool to help me solving the simple substitution ciphers.

   Tool: http://25yearsofprogramming.com/fun/ciphers.htm

2. Copy the encoded message above and paste it into the field of "Decode a cipher" in the tool page. Press "Start Without Help", then you could figure out the letter frequencies in the ciphered text.
3. The following is my steps in detail to decode the message.

   • Swap(LT)
   • Swap(ZH)
   • Swap(IE)
   • Lock(THE)
   • Swap(FI)
   • Swap(YS)
   • Lock(THIS)
   • Lock(IT)
   • Lock(TOO)
   • Swap(BN)
   • Lock(NOT)
   • Swap(WL)
   • Swap(XU)
   • Lock(SOLUTION)
   • Swap(KY)
   • Lock(YOU)
   • Swap(PC)
   • Swap(WA)
   • Swap(PG)
   • Lock(CHALLENGE)
   • Swap(KR)
   • Lock(YOUR)
   • Swap(QP)
   • Swap(ZD)
   • Lock(IMPRESSED)
   • Swap(KF)
   • Lock(FRIEND)
   • Swap(KV)
   • Lock(VERY)
   • Swap(ZK)
   • Lock(KEY)
   • Swap(QW)
   • Lock(WAS)
   • Swap(QB)
   • Lock(BY)

4. Well, after a long time, we got the answer.

   BY THE ALMIGHTY GOD YOU CAN READ THIS MY FRIEND I AM IMPRESSED VERY WELL DONE YOUR SOLUTION KEY IS SALSPPNEGEGD THIS LITTLE CHALLENGE WAS NOT TOO HARD WAS IT

5. Well done! By the way, the mapping relationship is like below:

   Plaintext alphabet: ABCDEFGHIJKLMNOPQRSTUVWXYZ
   Ciphertext alphabet:TAPHIRCZFJDWMBOQNSYLXEGUKV