Here is 1 saying encoded using a letter for letter replacement:

XCTG TG XCV OTYGX KAV XCKX'G LKTF HDIC KXXVUXTWU XW XCV ODXDYV, JCTIC TG K
BTXXBV TYWUTI GTUIV JV HKE UWX CKRV WUV.
-- KYXCDY IBKYZV