Method for accessing data in a secure manner, wherein - the data comprise a number of data sets, wherein - each of the data sets is assigned to an entity, preferably a user, and - the data sets are stored in encrypted form in a database, wherein a first decryption key assigned to a particular entity is used to decrypt the data sets assigned to the particular entity, - the first decryption keys are stored in a volatile memory (VMEM), - each of the first decryption keys assigned to the particular entity is encrypted by a first and at least a second encryption key assigned to the particular entity, and the at least two encrypted first decryption keys resulting therefrom are stored in a permanent memory unit (PMEM), - the access to the data sets stored in encrypted form in the database is handled by an access control device, wherein access policies indicating who can access the encrypted data sets and for what purpose are stored in the access control device, - each entity is assigned a number of access policies, - each of the at least two encrypted first decryption keys is assigned a different access policy, - all content in the volatile memory (VMEM) is deleted if the access policies are changed, and - after the volatile memory (VMEM) is erased - the encrypted first decryption keys are copied from the permanent memory (PMEM) into the volatile memory (VMEM), and - in the volatile memory (VMEM) the encrypted first decryption keys are decrypted by a first and at least a second second decryption key assigned to the particular entity, so that the first decryption key assigned to the particular entity is again present in decrypted form in the volatile memory (VMEM) and can be used to decrypt the data assigned to the particular entity and stored in the database. - the data comprise a number of data sets, wherein - each of the data sets is assigned to an entity, preferably a user, and - the data sets are stored in encrypted form in a database, wherein a first decryption key assigned to a particular entity is used to decrypt the data sets assigned to the particular entity, - each of the data sets is assigned to an entity, preferably a user, and - the data sets are stored in encrypted form in a database, wherein a first decryption key assigned to a particular entity is used to decrypt the data sets assigned to the particular entity, - the first decryption keys are stored in a volatile memory (VMEM), - each of the first decryption keys assigned to the particular entity is encrypted by a first and at least a second encryption key assigned to the particular entity, and the at least two encrypted first decryption keys resulting therefrom are stored in a permanent memory unit (PMEM), - the access to the data sets stored in encrypted form in the database is handled by an access control device, wherein access policies indicating who can access the encrypted data sets and for what purpose are stored in the access control device, - each entity is assigned a number of access policies, - each of the at least two encrypted first decryption keys is assigned a different access policy, - all content in the volatile memory (VMEM) is deleted if the access policies are changed, and - after the volatile memory (VMEM) is erased - the encrypted first decryption keys are copied from the permanent memory (PMEM) into the volatile memory (VMEM), and - in the volatile memory (VMEM) the encrypted first decryption keys are decrypted by a first and at least a second second decryption key assigned to the particular entity, so that the first decryption key assigned to the particular entity is again present in decrypted form in the volatile memory (VMEM) and can be used to decrypt the data assigned to the particular entity and stored in the database. - the encrypted first decryption keys are copied from the permanent memory (PMEM) into the volatile memory (VMEM), and - in the volatile memory (VMEM) the encrypted first decryption keys are decrypted by a first and at least a second second decryption key assigned to the particular entity, so that the first decryption key assigned to the particular entity is again present in decrypted form in the volatile memory (VMEM) and can be used to decrypt the data assigned to the particular entity and stored in the database.