Cryptography

Computer Science & Statistics at University of Rhode Island

Substitution Cipher Cryptanalysis Interactive Demo

STEP 1. INPUT PLAINTEXT AND CIPHERTEXT

The step shows letter frequencies for both plaintext and ciphertext. It also shows some of the most common digraphs and trigraphs for help in decoding the cipher text.

Ciphertext

XIAKGLTIZKSA RH GSV KIZXGRXV ZMW HGFWA LU SRWRMT RMULINZGRLM RM NLWVIM GRNVH XIAKGLTIZKSA RH XLMHRWVIVW Z YIZMXS LU YLGS NZGSVNZGRXH ZMW XLNKFGVI HXRVMXV ZMW RH ZUURORZGVW XOLHVOA DRGS RMULINZGRLM GSVLIA XLNKFGVI HVXFIRGA ZMW VMTRMVVIRMT XIAKGLTIZKSA RH FHVW RM ZKKORXZGRLMH KIVHVMG RM GVXSMLOLTRXZOOA ZWEZMXVW HLXRVGRVH VCZNKOVH RMXOFWV GSV HVXFIRGA LU ZGN XZIWH XLNKFGVI KZHHDLIWH ZMW VOVXGILMRX XLNNVIXV DSRXS ZOO WVKVMW LM XIAKGLTIZKSA.

RESULT OF STEP 1.

Table of Ciphertext letter frequencies.

Letter	Frequency	Letter	Frequency
A		N
B		O
C		P
D		Q
E		R
F		S
G		T
H		U
I		V
J		W
K		X
L		Y
M		Z

STEP 2. ATTEMPT TO DECODE THE CIPHERTEXT

At this point, enter in your guesses for the cipher text, and click on update to update the cipher text with the new letters. Reset will reset your guesses to all dashes.

Cipher Alphabet

Plaintext Alphabet

Cipher Alphabet

Plaintext Alphabet