Question 1

What is Format-Preserving Encryption?

Accepted Answer

FPE is an encryption method that produces ciphertext in the same format and length as the plaintext. For example, a 16-digit credit card number encrypts to another 16-digit number.

Question 2

What is the difference between FF1 and FF3-1?

Accepted Answer

Both are NIST-approved FPE algorithms. FF1 supports variable-length tweaks while FF3-1 uses a fixed 56-bit tweak. FF3-1 is generally faster but has more constraints.

Question 3

What is tokenization?

Accepted Answer

Tokenization replaces sensitive data with non-sensitive placeholders (tokens). FPE is often used for tokenization because the tokens maintain the original data format.

Question 4

Is FPE compliant with PCI DSS?

Accepted Answer

Yes, FPE using NIST SP 800-38G approved algorithms (FF1, FF3-1) is accepted for PCI DSS compliance when implemented correctly.

Format-Preserving Encryption

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Format-Preserving Encryption FAQ