"Hello, World" Key Equivocation
Given that the ciphertext KHOOR ZRUOG was encrypted using a C?sar cipher, what is the key equivocation? Clearly
there are 26 possible keys; here is the decryption of the ciphertext for each key:
key plaintext key plaintext key plaintext
A KHOOR ZRUOG R TQXXA IADXP J BYFFI QILFX
Z LIPPS ASVPH Q URYYB JBEYQ I CZGGJ RJMGY
Y MJQQT BTWQI P VSZZC KCFZR H DAHHK SKNHZ
X NKRRU CUXRJ O WTAAD LDGAS G EBIIL TLOIA
W OLSSV DVYSK N XUBBE MEHBT F FCJJM UMPJB
V PMTTW EWZTL M YVCCF NFICU E GDKKN VNQKC
U QNUUX FXAUM L ZWDDG OGJDV D HELLO WORLD
T ROVVY GYBVN K AXEEH PHKEW C IFMMP XPSME
S SPWWZ HZCWO B JGNNQ YQTNF
Assuming the plaintext is ordinary English (and not a code), the only possible plaintext is HELLO WORLD and the
key is D.