# Need help to decipher encrypted text

I am relatively new to deciphering text and I've been given these few puzzles to solve. I tried all available deciphering tools from Black Chamber and Rumkin tools but I can't seem to solve the puzzle. So far, I managed to solve 1 puzzle which uses the letter substitution. It will be helpful if you can solve the puzzle and explain the steps so I'll understand more. Thanks in advance.

a) JH Q PHUW GQXH Q VPQMSH

b) AAESTFRAEUTOTUAACSTARHDBCHOTYEYSTIMHISOTMN

c) HX VT YD HQ FV KX MI RK AU PC DR MB AB OE OP TE OD KP AD LM BW ZL AP MT NA ER UC DM CM NR SM DB QO NS

• If you tell us that you solved already one puzzle, maybe it will help us if you can post its solution. Commented Dec 6, 2016 at 7:55
• @Jason Ng- What if some of these involve a key? Are you sure they are without any keys? Commented Dec 6, 2016 at 9:27
• @Techidiot -Yes. All i know is that these are English that have been encrypted. I have to decrypt it and explain the method. This is the only hint "Attempts made could be brute force, informed guesswork or frequency analysis" Commented Dec 6, 2016 at 11:25
• @IAmInPLS- The first question uses the simple letter substitution. I tried doing it for other puzzle but no luck. So i assume it's using a different method, which i can figure it out Commented Dec 6, 2016 at 11:26
• The second one looks ike a transposition, even if it doesn't have many e's. Commented Dec 6, 2016 at 11:33

First one (firstly solved by Levieux) is

A monoalphabetic substitution cipher where J = B, H = E, Q = A, P = H, U = R, W = O, G = M, X = K, V = C, M = N, S = G:

BE A HERO MAKE A CHANGE

Second one is

a columnar transposition with the key 1 2 3 4 5:

AUTOMATATHEORYISTHESTUDYOFABSTRACTMACHINES

("Automata theory is the study of abstract machines")

Third one is

a Playfair cipher with the key SIMON:

CR YP TO GR AP HY IS TH EP RA CT IC EA ND ST UD YO FT EC HN IQ UE SF OR SE CU RE CO MX MU NI CA TI ON

("Cryptography is the practice and study of techniques for secure comxmunication" ("x" is a filler letter because it would be "MM" otherwise))

• Good. I identified third puzzle as playfair cipher, but i didn't get the key..
– KSR
Commented Dec 6, 2016 at 13:02
• Lovely! +1 Is it the same tool you mentioned days back? :) Commented Dec 6, 2016 at 13:04
• @Techidiot I honestly don't know what you mean, sorry. I sometimes use my own tools when decrypting ciphers, yes, but I don't think that's what you're addressing.
– user14478
Commented Dec 6, 2016 at 13:14
• Thank you so much guys ! I'm gonna study on it more and try doing it myself :) Commented Dec 6, 2016 at 14:22
• @Lukas Rotter- I'm curious how you find the keyword for the third question. Would you care to explain ? Thank you so much :) Commented Dec 6, 2016 at 14:46

The first one (probably the one OP already solved) could potentially be:

BE A HERO MAKE A CHANGE
Although other options might be possible as well...

• Hmm. Which method did you use to get that message ? Thank you for replying btw :) Commented Dec 6, 2016 at 11:28
• If you guess the first few letters (Q=A is pretty obvious and JH=BE is also very likely), then in quipqiup you get some very nice suggestions (you can type Q=A, J=B, H=E in the clues field) Commented Dec 6, 2016 at 12:30