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repository/docs/meta-data-services/node-storage-and-retrieval/README.md

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+# Node Storage and Retrieval
+
+## Properties
+
+### Encrypted properties (```d:encrypted```)
+Encrypted properties are stored as BLOBs in the database, but there is no additional handling for
+them. In particular, the ```NodeService``` does not encrypt or decrypt them. It only guarantees
+that properties of this type contain objects of type ```javax.crypto.SealedObject```. It is up to
+the implementor of a custom extension to handle encryption.
+The ACS provides the helper class ```MetadataEncryptor``` which provides key handling and a one-stop-shop
+for encryption. But custom implementations do not need to use it.