← Practice examsBANDWIDTH BROTHERS / SOAC 52–2026Codes & Ciphers

LESSON TOOLS FIELD NOTE 08

Cipherdesk.

You do the working.
Get the answer here.

Choose your system, enter the key and message, then compare the result with your solution.

01 Choose your system

Codes & Ciphers · lesson conventions

02 Set up your message

Operation

Lesson counting: NINE = 8 actual positions. A maps to S with a right shift.

Message body only. Omit headers and external indicators.

Calculated on your device. Updates as you type.

03 Your answer

READY

DECIPHERED TEXT

STUDY HARDX

COUNTER-CHECK YOUR WORK

Spacing is for readability. Nulls stay visible; remove them only when you know they were added.

Show me the working

FOLLOW THE LETTERS
Letter-by-letter trace
EXACT INPUT USED

Uppercase, without spaces or punctuation; includes any nulls inserted before enciphering.

+ External indicator helper No-borrow arithmetic · pp. 9, 11–12

Build the five-digit subtraction group, or recover the four key digits. The last digit is the sum of the first four, modulo 10.

RESULT23577

For a single transposition, key 05 is entered as 0005. For double transposition, keys 05 and 04 become 0504. The message count is a separate five-digit group.