Methods to Improve Secure Flash Programming

1. A method for loading multiple software objects into a computing device containing an embedded public root key and a stored first second level public key certificate when there is a different subsequent second level public key certificate associated with a second software object being loaded, the method comprising: receiving a first software object comprising a first second level public key certificate, an encryption signature and a first set of software from a programming source; determining that the second software object received is associated with the subsequent second level public key certificate that is different than the first second level public key certificate; when the subsequent second level public key certificate is the same as the first second level public key certificate, then validating the encryption signature associated with the second software object with the first second level public key certificate and writing the second software object to a non-volatile memory of the computing device; when the subsequent second level public key certificate is different from the stored first second level public key certificate, then validating the subsequent second level public key certificate with the embedded public root key; validating the encryption signature using the subsequent second level public key certificate; validating the second software object with their encryption signatures; and when the second software object is valid, then storing the subsequent second level public key certificate to the non-volatile memory and writing the second software object to a non-volatile memory.

2. The method of claim 1 , wherein the embedded public root key is an asynchronous public encryption key.

3. A vehicle comprising: an electronically controlled device; an electronic control unit (ECU) configured to control the electronically controlled device, the ECU containing an embedded public root key and a stored first second level public key certificate; and a boot loader, the boot loader configured to load software into the ECU when there is a different subsequent second level public key certificate associated with a second software object being loaded by: receiving a first software object comprising a first second level public key certificate, an encryption signature and a first set of software from a programming source; determining that the second software object received is associated with the subsequent second level public key certificate that is different than the first second level public key certificate; when the subsequent second level public key certificate is the same as the first second level public key certificate, then validating the encryption signature associated with the second software object with the first second level public key certificate and writing the second software object to a non-volatile memory of the computing device; when the subsequent second level public key certificate is different from the stored first second level public key certificate, then validating the subsequent second level public key certificate with the embedded public root key; validating the encryption signature using the subsequent second level public key certificate; validating the second software object with their encryption signatures; and when the second software object is valid, then storing the subsequent second level public key certificate to the non-volatile memory and writing the second software object to a non-volatile memory.

4. The vehicle of claim 3 , wherein the embedded public root key is an asynchronous public encryption key.