Here’s a randomnly generated unknown cipher. I’ll give a hint because all my ID tests got this one wrong. I needed the crib to solve it.
YIIXA JPKNL FCFFK XYCMJ XKGWF FPEFB FFNSE EIZRM OFYAM AGHIK ELXYB
VFFMO RIXJG CRJES UOOFF FDXFY XMFXM IEXMD SGZZF OHLLI JJVUP CFZRM
JFMEM ORJID XOFFF ONRKX YBFYT WFTCR MCTVE SFTFP UER.
caesar-shifted crib: FYLTTIBNQQNYITYTUN