Keetools

FPE Decryption

Format Preserving Encryption (FPE) refers to transforming data PlainText such that output is in the same format as input. FPE works on finite set of alphabets and typically used for

Encrypt 16 digit credit card number, so that the cipher text is another 16 digit number
Encrypt any English word, so that the cipher is another English word

Alphabet

0123456789

Enter or paste text to be decrypted

Method

Secret

Secret text something only you know

Key (Base64 Encoded)

Base64 encoded key

Cipher Mode

Decrypted data (Plain text)

How to use this tool?

This tool allows you to decrypt FPE encrypted cipher text to retrieve original plain text.

Select input Alphabet (either Numeric or Alphanumeric).
Enter or paste cipher text data that needs to be decrypted
Select same key option that was specified during encryption. If cipher text is encrypted, by another application, ensure you specify the Key that was used during encryption process
Enter secret or Key depending on option selected in previous step
Select same algorithm as encryption from the drop down
Click "Decrypt" to perform decryption operation

After decryption, plain text value will be displayed in the text box. If there is no plain text after clicking "Decrypt" button, then decryption operation has failed, check input values and try again

About AES Encryption & Decryption

Format Preserving Encryption (FPE) is a symmetric block cipher and there are two modes FF1 and FF3 approved by NIST SP 800-38G

Cipher Modes

There are two modes of operation for FPE

FF1
FF3

Plain Text

Text that needs to be encrypted is referred as Plain Text

Cipher Text

Encrypted text is referred to as Cipher Text