Method and apparatus for remotely verifying memory integrity of a device

An apparatus for verifying integrity of a memory of a remote device, the apparatus comprising:

• a random number generator for generating a random number for use in verifying integrity of the memory of the remote device;
• a storage for storing a random number function for use by the random number generator, for storing a memory filling map which comprises information about the filling in of each empty area of a block of memory to be verified using the random number, for storing a message authentication code (MAC) generating function for use in generating a local verification code, and for storing an integrity verifying function that, upon execution, identifies a first address and a last address of the block of memory to be verified;
• an analyzer for generating a local verification code using the MAC generating function, and for comparing the generated local verification code with a remote verification code received from the remote device which is based on the contents of a block of memory of the remote device that has had the empty areas filled with random numbers according to the memory filling map such that the block of memory has no empty areas;
• and
• a controller for transmitting the random number, the memory filling map, and the integrity verification function to the remote device, for receiving the remote verification code and a data status value from the remote device, and for determining the integrity of the memory of the remote device based on the data status value and a comparison result between the local verification code and the remote verification code.

A method for verifying integrity of a remote device, the method comprising:

• receiving, from a verifier, a random number sequence, a memory filling map, and an integrity verification function;
• executing the integrity verifying function to determine a first address and a last address of a block of memory to be verified;
• retrieving data from the memory based on the random number sequence and the memory filling map;
• obtaining a data status value by comparing a time difference with a threshold time, the time difference being obtained as a result of comparing a time of retrieving data from the first address of the memory with a time of retrieving data from the last address of the memory;
• filling in empty areas of the contents of the block of memory with the random number sequence according to the memory filling map such that the contents of the block of memory have no empty areas;
• and
• generating a remote verification code based on the contents of the block of memory having no empty areas, and sending the remote verification code together with the data status value to the verifier.

A remote device, comprising:

• a memory;
• a controller for executing an integrity verifying function to determine a first address and a last address of a block of memory to be verified;
• a read proxy for retrieving data from the memory using a verification parameter and the first and last address generated by the integrity verifying function, and for generating a status value based on a difference between a time of retrieving data from the first address of the memory and a time of retrieving data from the last address of the memory;
• a generator for filling in empty areas of the contents of the block of memory to be verified according to the verification parameter such that the contents of the block of memory have no empty areas, and for generating a remote verification code based on the contents of the block of memory that have no empty areas;
• and
• an interface for transmitting the remote verification code and the status value to a verifier.

A method for verifying integrity of a remote device, the method comprising:

• providing, by a verifier, an integrity verification function and a verification parameter to a remote device;
• executing the integrity verifying function to determine a block of memory to be verified;
• retrieving data from a memory of the remote device based on the verification parameter and the block of memory;
• determining a data status value by comparing a time of starting the data retrieval from the block of memory with a time of finishing the data retrieval from the block of memory;
• filling in empty areas of the contents of the block of memory to be verified according to the verification parameter such that the contents of the block of memory have no empty areas;
• generating a remote verification code based on the contents of memory that have no empty areas;
• and
• transmitting the remote verification code and the data status value to the verifier.

A remote device, comprising:

• a memory;
• an interface for receiving, from a verifier, an integrity verifying function and a memory filling map;
• a controller for executing the integrity verifying function to determine a first address and a last address of a block of memory to be verified;
• and
• a generator for filling in empty areas of the memory based on the memory filling map received from the verifier and the first address and the last address of the block of memory such that there are no empty areas in the contents from the first address and the last address of the block of memory, and for generating a remote verification code based on contents of the filled in memory that has no empty areas,
• wherein the remote verification code is transmitted to the verifier using the interface.