Update README.md

README.md

@@ -22,6 +22,15 @@ An encrypted string looks like this:
 
 AQAAANCMnd8BFdERjHoAwE/Cl+sBAAAAAQ5GMbx570mklMuNAyFRhgAAAAACAAAAAAAQZgAAAAEAACAAAACe7tibTHuzIsKVO2adNjiXU9TM9F1eR95Yk0Wk8Kzj7gAAAAAOgAAAAAIAACAAAAA7quouOuNvn7eicqjE9aa75UZN+TAbokD35hTXbE7UOBAAAADEFNscRxOqxxheOIVdtbiQQAAAAC+UCYzQFtF7uRyhjXKnqCii8OHUtmB5LwIgJTx46uLukKGsOp60rGVPGn6ufiYYCRXiCQPAmQEKjsEE1jwqZto=
 
+The package also supports machine specific encryption and encryption using entropy.
+
+Developing
+----------
+There is an application in `/cmd/stable` that creates a JSON file of encrypted values.  The purpose is to create a stable encrypted value and then verify it can still be decrypted after any changes are made.
+
+It creates a file named `domain.computer.user.stable.json` on the first run.  On subsequent runs it tries to decrypt the values in the JSON file.  It currently only tests per-user encryption.  But this should allow testing of machine encryption and encryption with entropy.
+
+
 References
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