Patent ID: 7047421

Claim:
A content provider, comprising: a database comprised of encrypted content; a compressed key generator that generates a compressed key from which a first key can be derived to gain access to a first data subset of the database, and a second key can be derived to gain access to a second data subset of the database; an integer modulus generator that generates an integer modulus that is the product of two or more prime numbers; a random integer generator that selects a random value having a value between one and one less than the modulus, the random value having no factors in common with the modulus; a prime set derivation module that derives a prime set that includes a prime number for each datum in the database, each prime number being uniquely associated with a datum in the database; and a prime subset derivation module that derives a prime subset that includes the prime numbers from the prime set that are associated with the data contained in the first data subset.