On the Subject of the Burrows-Wheeler CM
A machine that knows no bounds when it comes to ciphers.
- Start with a list of N empty lines, where N is the length of the encrypted word.
- Prepend the list with the letters of the encrypted word vertically (one letter per row).
- Sort the rows alphabetically.
- Repeat steps 2–3 a total of N times.
Let K be the number shown on the top screen. The Kth row is your decrypted word.
Example
Encrypted word: ESUDLP
K = 4
E S U D L P |
D E L P S U |
ED SE UL DP LS PU |
DP ED LS PU SE UL |
EDP SED ULS DPU LSE PUL |
DPU EDP LSE PUL SED ULS |
EDPU SEDP ULSE DPUL LSED PULS |
DPUL EDPU LSED PULS SEDP ULSE |
EDPUL SEDPU ULSED DPULS LSEDP PULSE |
DPULS EDPUL LSEDP PULSE SEDPU ULSED |
EDPULS SEDPUL ULSEDP DPULSE LSEDPU PULSED |
DPULSE EDPULS LSEDPU PULSED ← #4 SEDPUL ULSEDP |
Decrypted Word: PULSED