NIST’s draft FPE update bans FF3, mandates FF1 and larger domains
The second public draft of NIST SP 800‑38G Rev. 1 removes the FF3 method after cryptanalysis showed weaknesses, leaving FF1 as the sole approved format‑preserving encryption. It also raises the minimum domain size to one million and disallows the inverse AES cipher and floating‑point arithmetic, tightening security for real‑world deployments.