Abstract: According to one aspect of the technique of the present disclosure, there is provided a method for securely communicating data. The method includes: (a) establishing a first encryption scheme, a data integrity checking scheme, an encryption key and an authentication key through a communication connection with a receiver; (b) generating a random key; (c) generating secure data including random key information obtained by encrypting the random key using the encryption key and the first encryption scheme; authentication information generated based on the random key, the data integrity checking scheme and the authentication key; and data information obtained by encrypting data using the random key and a second encryption scheme whose operation load is lower than that of the first encryption scheme; and (d) transmitting the secure data to the receiver.

Abstract: A method includes (a) receiving i-th data among first to n-th data transmitted in a multicast manner from a firmware providing apparatus, (b) acquiring partitioning information thereof, a MAC chaining value, length information, i-th firmware data, and MAC from the i-th data, (c) authenticating the MAC chaining value of the i-th firmware data, the length information, and the i-th firmware data by comparing a MAC of the i-th firmware data with a value computed by a first MAC generation algorithm, which uses the MAC chaining value of the i-th firmware data, the length information, and the i-th firmware data as a relevant input; (d) authenticating the order of the i-th firmware data by using the MAC chaining value of the i-th firmware data and a second MAC generation algorithm; and (e) obtaining the firmware by combining a first to an n-th firmware data obtained by executing (a) to (d).