 const uint8_t HASH_LEN = 20; // 160-bit. The other 32 bits for timestamp
 uint8_t correct_hash[HASH_LEN];
 uint8_t hash[HASH_LEN]; // for the incoming hash?
+
+// For timestamping messages
+time_t timestamp;
 
 MCP_CAN CAN(SPI_CS_PIN);                                    // Set CS pin
 

#include <mcp_can.h>
#include <SPI.h>
#include <SpritzCipher.h>
#include "can_constants.h"

// the cs pin of the version after v1.1 is default to D9

}


void StampTime(uint8_t *buf)
{
    // Get current time
    timestamp = now();

    Serial.print("Timestamp: ");
    Serial.print(day(timestamp));
    Serial.print(" - ");
    Serial.print(hour(timestamp));
    Serial.print(":");
    Serial.print(minute(timestamp));
    Serial.print(":");
    Serial.println(second(timestamp));

    // Store the timestamp
    buf[0] = day(timestamp);
    buf[1] = hour(timestamp);
    buf[2] = minute(timestamp);
    buf[3] = second(timestamp);
}


// Sends the 3 authentication messages
void SendAuthMessages()
{
