Cryptology Through History and Inquiry

Start by setting the index to s and the key letter to C. Then you can start translating the plaintext to ciphertext. Remember that you need to write the key letter down each time you change it, the plaintext for Alberti are the uppercase letters around the outside of his formula, and sometimes you need to leave letters out or make substitutions since not all the letters are available. In the end you should have something like: Cdmb sxb G&h tmm Xxkpg& ke Clm nnhff.

Write down the plaintext with the key above it and then, using the key letter to indicate the row and plain letter the column, look up the ciphertext in the table.

france france france france france france f
hopeis agoodb reakfa stbuti tisaba dsuppe r
MFPRKW FXOBFF WVAXHE XKBHVM YZSNDE IJUCRI W

Write out the ciphertext with the key word written above it as before. Now look use each key letter to tell which row to look in and slide your finger along to the cipher letter; the column header is your plaintext letter.

state state state state state state state state ...
LAEKI SKEGS KXCKI LLTHW MVCXW KBTBW LAEKI KNLMS ...
there are ...

write out the message with the key above, like Vigenere's polyalphabetic cipher, but now the key is essentially the message its self. Above the first letter is our key letter, then after that you write down the message. Thne lok up the key letter on the side of the table and find the plain letter in the corresponding row. This last step is a little tricky because the letters are in pairs, so if the key letter is S and we need a plain t the cipher letter will be F.

FOBST ACLES ARETH OSEFR IGHTF U ...
obsta clesa retho sefri ghtfu l ...
ERGFO OUMIO FTLXF CSPHN OQATA M ...

As before write out the message, place the key letter above the first plaintext letter, and write out the rest of your message after that as a key. Then, using the modern Vigenere table, the key letters in the top row tell you which row to look in and the plain letters gives you the column.

SSUCC ESSIS NOTFI NALFA ILURE ISNOT FATAL ITIST HECOU ...
succe ssisn otfin alfai lurei snotf atali tisth ecour ...
KMWEG WKAAF BHYNV NLQFI TFLVM AFBHY FTTLT BBALA LGQIL ...

To decipher this you need to decipher the first character with the X, look in row X for the A and then there is a d at the top of that column. Now repeaet the process with the D you just found and the R, this is how you get the o. Keep repeating this process until you find the message.

Xdonu tsist herea nythi ngthe ycant domat tgroe ning
ARBHN LAALA LVVEN LRAPV TZALC ACNGW RAMTM ZXFSR VVT
donut sisth erean ythin gthey cantd omatt groen ing

Create a table with three three columns and four rows. Label the rows with the keys and the columns with A, B, and C. Write down the message character by character with the keys at the side telling you which columns to write the characters in. Finally, write down the blocks of text from left to right and top to bottom.

Cipher Table:

         A   B   C
ACB :   WGI RWE EIV
BCA :   NLI EOR IUS
CAB :   TBY AEM ODT
ABC :   KAA IUN NN

Final cipher text:

WGI RWE EIV NLI EOR IUS TBY AEM ODT KAA IUN NN

Cipher Table:

         A   B   C
CBA :   AHF HDE INR
ABC :   VAO ETR LEE
BCA :   ENI ODI VID
CAB :   JQI UUN DIE
ACB :   SIE IYI TTX
BAC :   EHE CTL AE

Completed Message:

AHF HDE INR VAO ETR LEE ENI ODI VID JQI UUN DIE SIE
IYI TTX EHE CTL AE

Set up a table with columns labeled A, B, C, and rows labeled with the keys. Write each block of text into the table from right to left and top to bottom. Finally, read the characters out of the table one at a time based in the order given by the keys.

        A      B      C
ABC : ISUIIP TTRNLE IADOLA
BCA : OTTSM  SREUIR NSSRAE
BCA : NOYVA  TOIES  IHNLH
ACB : TLBEK  EOTWS  HDUSE

Completed Message:

“It is not in the stars to hold our destiny, but in ourselves.” - William Shakespeare