When encryption is enabled PSMDB (with
PSMDB-273 fixed) can create encrypted data files which are for further investigation. For example during rollback files with documents removed by rollback process are created. Those files are in BSON format and are encrypted if encryption is enabled. (https://docs.mongodb.com/manual/core/replica-set-rollbacks/#collect-rollback-data)
This tool differs from the tool described in PSMDB-240 because that other tool is for decrypting encrypted wiredTiger instance (keydb database which stores encryption keys for MongoDB databases).