Device, system and method for token based outsourcing of computer programs

A system for token-based obfuscation of secret information, the system comprising:

• a second party device comprising:
• a processor configured to:
• receive from a first party device an obfuscated program T′ that is obfuscated by encoding the original program T with the set of secret encryption keys SK,
• receive from a first party device a token of the data Token(D) that is obfuscated by encoding the original data D with the set of secret encryption keys SK, and
• evaluate the obfuscated program T′ on the token of the data Token(D) to generate a result equivalent to evaluating the original program T on the original data D if the same set of secret encryption keys SK is used to obfuscate the original program T and the original data D, without exposing the original program T to the second party.

A method for token-based obfuscation of secret information, the method performed at a first party device comprising:

• storing a secret original program T and original data D;
• and
• retrieving a set of secret encryption keys SK,
• obfuscating the original program T with the set of secret encryption keys SK to generate an obfuscated program T′,
• obfuscating the original data D with the set of secret encryption keys SK to generate a token of the data Token(D), and
• transferring the obfuscated program T′ and the token of the data Token(D) to a second party device where the obfuscated program T′ is evaluated on the token of the data Token(D) to generate a result equivalent to evaluating the original program T on the original data D if the same set of secret encryption keys SK is used to obfuscate the original program T and the original data D, without exposing the original program T to the second party.

A method for token-based obfuscation of secret information, the method performed at a second party device comprising:

• receiving from a first party device an obfuscated program T′ that is obfuscated by encoding the original program T with the set of secret encryption keys SK;
• receiving from a first party device a token of the data Token(D) that is obfuscated by encoding the original data D with the set of secret encryption keys SK;
• and
• evaluating the obfuscated program T′ on the token of the data Token(D) to generate a result equivalent to evaluating the original program T on the original data D if the same set of secret encryption keys SK is used to obfuscate the original program T and the original data D, without exposing the original program T to the second party.