Patent ID: 8397078
Filing Date: 2013-03-12
Classification: H04N

Abstract:
1. A computer-implemented method for authenticating and executing a program, comprising: downloading, from a predetermined server, a program made up of at least one data file, in a directory structure, which requires tamper checking, according to information identifying a storage location of the program, authenticating the downloaded at least one data file requiring tamper checking, and storing the program into a broadcast receiver, the information being specified in a transport stream, the server being connected to a network; and executing the authenticated program, wherein the authenticating includes executing authentication operations that include: verifying whether two hash values match, one of the hash values being calculated from the at least one data file requiring tamper checking, the at least one data file being downloaded into the broadcast receiver and listed in a hash file so as to have a directory structure which is a same as a directory structure of the program stored in the server, based on a directory and a data file listed in the hash file included in a directory constituting the directory structure, and an other hash value being stored in the hash file listing the at least one data file; verifying a validity of a certificate file included in the program; and verifying whether a decrypted value and a hash value match, the decrypted value being obtained by decrypting a signature value of a signature file included in the program using a public key of a leaf certificate included in the certificate file of the program, the hash value being calculated from a hash file located in a top directory of the program, wherein the program is authenticated and stored when all of the following are satisfied: the two hash values are verified to be matching; the certificate file is verified to be valid; and the decrypted value and the hash value are verified to be matching, executing the authenticated program includes: verifying whether the certificate file included in the stored program is valid, and during said executing, the stored program is authenticated a second time and executed only when the certificate file included in the stored program is verified to be valid during verifying whether the certificate file included in the stored program is valid, and wherein the authenticating includes executing all of the authentication operations without executing the program, and the executing the authenticated program includes executing at least one and less than all of the authentication operations, verifying a validity of a certificate file included in the program includes: