Data protection using functional encryption

A method of limiting data usage for certified purposes during runtime by using functional encryption, comprising:

• retrieving data from a memory in response to a query for data received from an application;
• encrypting the queried data using a public key which is paired with a function private key and created by a purpose certifier;
• sending the encrypted queried data to the application to be used by a function of the application, wherein the function is operated on the encrypted queried data using the function private key which is created by the purpose certifier after verifying that actual usage of at least one data type by the function is compliant with at least one declared usage of the function.

A method of using data for certified purposes by using functional encryption, comprising:

• receiving a function private key which is created for a function from a master private key paired with a public key, wherein the function private key is created by a purpose certifier after verifying that actual usage of at least one data type by the function is compliant with at least one declared usage of the function;
• receiving encrypted data which is encrypted using the public key;
• operating the function on the encrypted data using the function private key to extract an unencrypted result of the function for the data.