What Techniques Can Help Decode This Complex Cipher?

  • Context: Undergrad 
  • Thread starter Thread starter everQuest
  • Start date Start date
Click For Summary
SUMMARY

The cipher presented in the discussion is identified as a rail fence cipher with a depth of 3. Initial attempts at frequency analysis suggested it was not a simple substitution cipher, as common letters like E and I appeared frequently. The final letter 'N' was speculated to be part of the key, but ultimately, the solution involved reconstructing the message by placing letters in a zigzag pattern. The decoded message reveals a series of phrases attributed to notable figures, indicating the cipher's complexity and the need for specific decoding techniques.

PREREQUISITES
  • Understanding of frequency analysis in cryptography
  • Familiarity with rail fence cipher techniques
  • Knowledge of substitution and transposition ciphers
  • Basic skills in pattern recognition and problem-solving
NEXT STEPS
  • Research advanced techniques for decoding rail fence ciphers
  • Learn about frequency analysis for different languages
  • Explore other classical ciphers such as Vigenère and Playfair
  • Practice with online cipher-solving tools and simulators
USEFUL FOR

Cryptography enthusiasts, puzzle solvers, and anyone interested in decoding complex ciphers will benefit from this discussion.

everQuest
Messages
2
Reaction score
0
Need help to solve this cipher...

Hi everyone,

ive been given the following cipher:

HSRFB YEIOG MVMMA RDETD AEOSE UIOII GHRAL BLIPE
DIEJL TOBOR PALBT AWIAP TEATO DOTDU DWRIL KYUOI
EYOEO YAIYN FINSH LSWRS FIENU ROWRI JSLKT SYMAL
NWTTE OKNIL EAKIE NEEDN EAWTJ SSUEI EHMVE IMTES
IADLI LEAKH MGCOD SRNIA ILWSE NEDET VLTFL DETAO
OLWNE DTEAS IIHCD BCKDN CYHUN KEIGH HNLBC EIRFG N

(6 lines, 8 blocks on each line, 5 characters in each block, except last line having letter N standing alone)

and no hint is given. I've tried to do frequency analysis, it shows that letter E appears the most (29 times), then I (25) and then L,A,T,O. So i guess it is unlikely to be substitution cipher.

But then i don't know what to do next,ive tried transposition, but it didnt show any useful message.

could anyone give me some advice to solve this cipher?

thanks,

PS: i reckon the last letter N,which stands separately from the block, could be the key,but i can't figure out how to use it.
 
Mathematics news on Phys.org


everQuest said:
Hi everyone,

ive been given the following cipher:

HSRFB YEIOG MVMMA RDETD AEOSE UIOII GHRAL BLIPE
DIEJL TOBOR PALBT AWIAP TEATO DOTDU DWRIL KYUOI
EYOEO YAIYN FINSH LSWRS FIENU ROWRI JSLKT SYMAL
NWTTE OKNIL EAKIE NEEDN EAWTJ SSUEI EHMVE IMTES
IADLI LEAKH MGCOD SRNIA ILWSE NEDET VLTFL DETAO
OLWNE DTEAS IIHCD BCKDN CYHUN KEIGH HNLBC EIRFG N


(6 lines, 8 blocks on each line, 5 characters in each block, except last line having letter N standing alone)

and no hint is given. I've tried to do frequency analysis, it shows that letter E appears the most (29 times), then I (25) and then L,A,T,O. So i guess it is unlikely to be substitution cipher.

But then i don't know what to do next,ive tried transposition, but it didnt show any useful message.

could anyone give me some advice to solve this cipher?

thanks,

PS: i reckon the last letter N,which stands separately from the block, could be the key,but i can't figure out how to use it.

Try to pin down the the language. Let's assume english. Run a single letter frequency count. If no luck, try di-graph then tri-graph frequency counts...look at the results carefully. I ran a frquency count on your message and it does follow the common pattern of a substatution cipher. Suggest you compair your frequency analysis with the letter frequency analysis of other languages. Becasue the frequency count show preference to certain letters over others, suggest this is not a machine cipher (Enigma), or an enciphered code (Dictionary Code)... If this was from a friend...what prob. words or subject should we look for? Hummm...Interesting! I shall endeavor to assist. At least I got you started. Keep me posted! BlackChamber
 


It's the railfence cypher with a depth of 3. Since this was a post necroed from 2006 I'm thinking I'm not spoiling anything by giving it away. With the spaces put back in:

he last words of ted bundy were id like you to give my love to my family and friends the last words of aileen wuornos were id just like to say I am sailing with the rock and ill be back like independence day with jesus june like the movie big mothership and all ill be back the magic word is frangipanit

For example, at the start:
Code: 
h . . . s . . . r
. e . a . t . o .
. . l . . . w . .

Only real question is if the t at the end is part of the password or goes in front of the "he" at the start to make "the". Probably, since "frangipani" is a real word.