Patent ID: 7797541

Claim:
A method for providing cellular telephone service in a telephone service provider, comprising the steps of: receiving a data descriptor transmitted from a cellular telephone to said telephone service provider, said data descriptor comprising an identity public key of said cellular telephone for transforming data according to a first public/private key encryption algorithm, attribute data of said cellular telephone, and a digital signature of said identity public key and said attribute data, said digital signature representing an encryption of data derived from said identity public key and said attribute data, said encryption being according to a second public/private key encryption algorithm using a signature private key; providing source test data, said step of providing source test data being performed by said telephone service provider; performing a pair of complementary data transformations of said source test data to produce resultant test data, by: (a) performing a first data transformation of said pair of complementary data transformations according to said first public/private key encryption algorithm using said identity public key, said performing a first data transformation step being performed by said telephone service provider, and (b) requesting said cellular telephone to perform a second data transformation of said pair of complementary data transformations according to said first public/private key encryption algorithm using an identity private key stored in said cellular telephone, and receiving the results of said second data transformation; comparing said source test data to said resultant test data, said comparing step being performed by said telephone service provider; verifying that said digital signature matches said identity public key and said attribute data, wherein verifying that said digital signature matches said identity public key and said attribute data is performed by said telephone service provider and comprises decrypting said digital signature according to said second public/private key encryption algorithm using a signature public key, and comparing the decrypted digital signature to said data derived from said identity public key and said attribute data; providing cellular telephone service to said cellular telephone depending on whether said source test data matches said resultant test data and whether said digital signature matches said identity public key and said attribute data.