Patent ID: 7761704

Claim:
A method for accessing a database object in an encrypted database system, the method comprising: receiving an access-request to access the database object's state at time T which occurred in the past, wherein the database object was encrypted using different keys at different times in the past, wherein the different keys are stored and associated with timestamps to indicate which key was used for encrypting the database object at any given time, and wherein each key is associated with a key-identifier, the key-identifier comprising: a unique random number, a transaction-identifier which uniquely identifies a transaction and which is used to determine an order in which the database object needs to be expired, wherein the database object is created as part of the transaction, and a global database identifier which identifies a database among a collection of databases in a distributed database system; determining a key which was used to encrypt the database object at time T, wherein a timestamp associated with the key indicates that the key was used to encrypt the database object at time T; and decrypting the database object's state at time T using the key.