0 1 2 Secure Write Request Include a digital signature along with the control data Algorithm Algorithm used to compute the digital signature For future proof NONE No digital signature For test purposes only AES-GMAC-64 64 bit AES signature algorithm is used ECC-256 256 bit ECC signature algorithm is used Timestamp Timestamp value is the number of seconds since January 1, 2000 Milliseconds Millisecond counter 0-999 Sequence Sequence number of request Shall be advanced for each request Role Signing key used 0-5 Each controller is assigned a key index that maps to their access control role N Number of registers comprising the digital signature. The value of N must be at least 4 (64 bits) X Number of (offset, value) pairs being written A max of 50 (offset, value) pairs are allocated Offset1 Offset of control register to write value to Value1 Value to write to control register at offset DS Digital Signature The DS covers all registers from X to N and is N registers in length