Revise README for java-fpe clarity and details

Updated README to clarify the purpose and implementation details of the java-fpe library.

Author: bschoening

README.md

@@ -14,10 +14,9 @@
 
 # ff3 - Format Preserving Encryption in Java
 
-An implementation of the NIST approved FF3 and FF3-1 Format Preserving Encryption (FPE) algorithms in Java.
+java-fpe provides Format-Preserving Encryption (FPE) for Java, allowing sensitive data such as credit card numbers, account IDs, phone numbers, and dates to be encrypted **while preserving their original format**. This is useful in systems that require encrypted data to maintain fixed-length, numeric, or structured formats.
 
-This package follows the FF3 algorithm for Format Preserving Encryption as described in the March 2016 NIST publication 800-38G _Methods for Format-Preserving Encryption_, 
-and revised on February 28th, 2019 with a draft update for FF3-1.
+It implements the NIST-approved FF3 and FF3-1 algorithms as specified in NIST Special Publication 800-38G and includes the revisions on February 28th, 2019 with a draft update for FF3-1.
 
 * [NIST Recommendation SP 800-38G (FF3)](http://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38G.pdf)
 * [NIST Recommendation SP 800-38G Revision 1 (FF3-1)](https://nvlpubs.nist.gov/nistpubs/SpecialPublications/NIST.SP.800-38Gr1-draft.pdf)