# security in format preserving encryption

In format preserving encryption an attacker knows the format and data type of the plain text. The format of the plain text and cipher text are same. usually cipher text are unreadable form. then how FPE is secure?what are all the possible attacks on FPE cipher?

Usually FPE is $Rank-LPE-DeRank$ Where LPE is length preserving encryption. The advantages of FPE schemes Preserving Formats and Lengths could be used against it too.
Length Preserving This might aide to brute force attacks if the domain is too small. For example encrypting an IP Address using FPE , the Cipher text is just $32$ bits, Where as encrypting with traditional AES would result in $128$ bits.