A computerized method (10, 30, 40, 50, 60) of managing security of at least a portion of first tenant data of a first tenant of a multitenant database system (100, 200) that stores at least the first tenant data of the first tenant and second tenant data for a second tenant, the first tenant data of the first tenant being stored in an immutable storage (108, 118) of the multitenant database system (100, 200) associated with a first tenant identifier, and second tenant data of the second tenant being stored in the immutable storage (108, 118) of the multitenant database system (100, 200) associated with a second tenant identifier, wherein any portion of the first tenant data and the second tenant data logically belongs to at least one of the same database object in the multitenant database system (100, 200), the method (10, 30, 40, 50, 60) comprising: segregating, at a memory storage coupled to the multitenant database system (100, 200), the first tenant data of the first tenant from at least the second tenant data of the second tenant, based on the first tenant identifier; retrieving, from a key cache memory based on the first tenant identifier, a first encryption key associated with the first tenant to encrypt one or more fragments of the first tenant data, wherein the first encryption key is different from a second encryption key associated with the second tenant; encrypting, at the multitenant database system (100, 200), at least one of the one or more fragments of the first tenant data based on the retrieved first encryption key; encrypting, at the multitenant database system (100, 200), cross-tenant data using a system (100, 200, 1200, 1200a-d) encryption key that is different from the first encryption key and the second encryption key, wherein the cross-tenant data is data for the first tenant and the second tenant; generating, at the multitenant database system (100, 200), non-encrypted header information for each of the encrypted one or more fragments of the first tenant data, wherein the header information has metadata including the first tenant identifier; and storing, in the immutable storage (108, 118), the encrypted one or more fragments of the first tenant data, the corresponding non-encrypted header information, and the encrypted cross-tenant data. segregating, at a memory storage coupled to the multitenant database system (100, 200), the first tenant data of the first tenant from at least the second tenant data of the second tenant, based on the first tenant identifier; retrieving, from a key cache memory based on the first tenant identifier, a first encryption key associated with the first tenant to encrypt one or more fragments of the first tenant data, wherein the first encryption key is different from a second encryption key associated with the second tenant; encrypting, at the multitenant database system (100, 200), at least one of the one or more fragments of the first tenant data based on the retrieved first encryption key; encrypting, at the multitenant database system (100, 200), cross-tenant data using a system (100, 200, 1200, 1200a-d) encryption key that is different from the first encryption key and the second encryption key, wherein the cross-tenant data is data for the first tenant and the second tenant; generating, at the multitenant database system (100, 200), non-encrypted header information for each of the encrypted one or more fragments of the first tenant data, wherein the header information has metadata including the first tenant identifier; and storing, in the immutable storage (108, 118), the encrypted one or more fragments of the first tenant data, the corresponding non-encrypted header information, and the encrypted cross-tenant data.