The following is an example of a real-life scenario that was recently encountered. A substitution cipher is when letters are replaced by other letters to form a new, hidden message. During a CTF that was hosted by "NullCon" we came across a challenge that looked like a substitution cipher. The challenge was:
Find the key:
TaPoGeTaBiGePoHfTmGeYbAtPtHoPoTaAuPtGeAuYbGeBiHoTaTmPtHoTmGePoAuGe ErTaBiHoAuRnTmPbGePoHfTmGeTmRaTaBiPoTmPtHoTmGeAuYbGeTbGeLuTmPtTm PbTbOsGePbTmTaLuPtGeAuYbGeAuPbErTmPbGeTaPtGePtTbPoAtPbTmGeTbPtEr GePoAuGeYbTaPtErGePoHfTmGeHoTbAtBiTmBiGeLuAuRnTmPbPtTaPtLuGePoHf TaBiGeAuPbErTmPbPdGeTbPtErGePoHfTaBiGePbTmYbTmPbBiGeTaPtGeTmTlAt TbOsGeIrTmTbBiAtPbTmGePoAuGePoHfTmGePbTmOsTbPoTaAuPtBiGeAuYbGeIr TbPtGeRhGeBiAuHoTaTbOsGeTbPtErGeHgAuOsTaPoTaHoTbOsGeRhGeTbPtErGePoAuGePoHfTmGeTmPtPoTaPbTmGeAtPtTaRnTmPbBiTmGeTbBiGeTbGeFrHfAuOs TmPd