Sony patents secure data checks for connected devices

1. An information processor comprising: a memory storing a program, and at least one processor configured to execute the program to perform operations comprising: protecting at least a portion of a first communication in which a frame is transmitted or received, wherein the frame includes first packet data of multiple lines, the frame includes a packet header and a packet data payload, and the packet data payload is separated into an extended packet header and a legacy payload including the first packet data; performing an arithmetic operation of a first message authentication code that protects a portion or an entirety of the first packet data, on a basis of first communication message authentication policy information indicating which first communication message authentication policy is selected from alternatives including a first message authentication policy, a second message authentication policy, a third message authentication policy, and a fourth message authentication policy, wherein the first communication message authentication policy information is stored in the extended packet header within the packet data payload, the first message authentication policy is a policy that applies the protection by the first message authentication code to the entirety of the first packet data, the second message authentication policy is a policy that excludes the protection by the first message authentication code for a portion of the first packet data in a line vertical direction, the third message authentication policy is a policy that excludes the protection by the first message authentication code for a portion of the first packet data in a line horizontal direction, and the fourth message authentication policy is a policy that excludes the protection by the first message authentication code for the entirety of the first packet data; storing, in a functional register, information related to an upper limit of a data amount that can be held for an arithmetic operation of a second message authentication code that protects at least a portion of a second communication; verifying the second message authentication code for a data group within a range not exceeding the upper limit of the data amount; and inhibiting, by the at least one processor, execution of processing of write data, read data, or decryption in response to successful verification of the second message authentication code.