About Transparent Data Encryption (TDE)
Transparent Data Encryption (TDE) protects sensitive at-rest data using a local encryption key file.
-
Configuration file properties: Protects LDAP search password, LDAP truststore password, SSL truststore passwords.
-
System resources: Protected properties using the same key for the
system.batchlogandsystem.paxostables, hint files and commit logs. -
Database tables and SSTable indexes: Protects all data in the table and on-disk SSTable indexes. Different tables can use different keys.
SSTable data files are immutable once they have been flushed to disk and are only encrypted during the write to disk. To encrypt existing data, use the
nodetool upgradesstableswith the-aoption to rewrite the tables to disk with encryption.When TDE is enabled, all header data in indexes are encrypted including partition keys in SSTable indexes. This feature is designed to protect sensitive data that might be present in the primary key. When non-decryptable SSTables are present, HCD issues an error message during startup. If the error is ignored because the disk failure policy is specified as either
ignoreorbest_effort, then HCD skips the non-decryptable SSTable and therefore ignores its content on queries without issuing a warning or error.
Consequently, HCD cannot access SSTables that are not decryptable.
Data that is not encrypted
HCD does not encrypt the following:
-
Database files other than the commit log
-
SSTable data files such as offsets and tokens
-
SAI indexes
Requirements
To use the HCD TDE feature, enable the Java Cryptography Extension (JCE).
|
Starting in JDK |
For more information, see the Release Notes for JDK 8u161.
