In an example, a method includes receiving a data package, the data package including a contact identification and a message payload; in response to determining that a key for the contact identification does not exist in a contact table: generating a key for the contact identification; and updating the contact table with the generated key to indicate an association between the key and the contact identification; calculating a hashed identification based on the generated key and contact identification; and associating the message payload with the hashed identification in a message table.