System and methods of the disclosed subject matter provide segregating, at a memory storage coupled to a multitenant database system, first tenant data of a first tenant from at least second tenant data of a second tenant, based on a first tenant identifier. A first encryption key associated with the first tenant may be retrieved from a key cache memory based on the first tenant identifier, to encrypt one or more fragments of the first tenant data. The fragments of the first tenant data may be encrypted based on the retrieved encryption key. Non-encrypted header information may be generated for each of the encrypted fragments of the first tenant data, where the header information may have metadata including the first tenant identifier. The encrypted fragments of the first tenant data and the corresponding non-encrypted header information may be stored in the immutable storage.