In cryptography, a Caesar cipher, also known as Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. [...]
#!/bin/sh IN="MJHVIZN ZPIO YJHPN" for I in $(seq 25); do echo $I $IN | tr $(printf %${I}s | tr ' ' '.')\A-Z A-ZA-Z done
This outputs:
1 NKIWJAO AQJP ZKIQO 2 OLJXKBP BRKQ ALJRP 3 PMKYLCQ CSLR BMKSQ 4 QNLZMDR DTMS CNLTR 5 ROMANES EUNT DOMUS 6 SPNBOFT FVOU EPNVT 7 TQOCPGU GWPV FQOWU 8 URPDQHV HXQW GRPXV 9 VSQERIW IYRX HSQYW 10 WTRFSJX JZSY ITRZX 11 XUSGTKY KATZ JUSAY 12 YVTHULZ LBUA KVTBZ 13 ZWUIVMA MCVB LWUCA 14 AXVJWNB NDWC MXVDB 15 BYWKXOC OEXD NYWEC 16 CZXLYPD PFYE OZXFD 17 DAYMZQE QGZF PAYGE 18 EBZNARF RHAG QBZHF 19 FCAOBSG SIBH RCAIG 20 GDBPCTH TJCI SDBJH 21 HECQDUI UKDJ TECKI 22 IFDREVJ VLEK UFDLJ 23 JGESFWK WMFL VGEMK 24 KHFTGXL XNGM WHFNL 25 LIGUHYM YOHN XIGOM
The only line which makes sense is 5 ROMANES EUNT DOMUS, giving us our solution.
@lolamby
Or you could use the caesar command from the bsdgames packages:
corsac@scapa: echo MJHVIZN ZPIO YJHPN |caesar
ROMANES EUNT DOMUS
(yes, it automatically finds the right key using letter frequencies)
Corsac [x]
— lamby
"People called Romans they go the house?" - _Much_ more impressive if it translated it properly as
"Romani ite domum" (including hte locative). :)
Don't know if the Debian package for Crank also does Caesar slide ...
Andy Cater [x]
When I want to decrypt my own words, I put the phrase in. But something happens, and every output is the same as the input.. Why? What am I doing wrong?
Dominick [x]
Hi, nice tip. I didn't know abot the dot in tr, how does it works? I don't see it in the manual....
Thanks!
Fa [x]