Validating sensitive data from an application processor to modem processor

An electronic circuit 120 includes a more-secure processor ( 600 ) having hardware based security ( 138 ) for storing data. A less-secure processor ( 200 ) eventually utilizes the data. By a data transfer request-response arrangement ( 2010, 2050, 2070, 2090 ) between the more-secure processor ( 600 ) and the less-secure processor ( 200 ), the more-secure processor ( 600 ) confers greater security of the data on the less-secure processor ( 200 ). A manufacturing process makes a handheld device ( 110 ) having a storage space ( 222 ), a less-secure processor ( 200 ) for executing modem software and a more-secure processor ( 600 ) having a protected application ( 2090 ) and a secure storage ( 2210 ). A manufacturing process involves generating a per-device private key and public key pair, storing the private key in a secure storage ( 2210 ) where it can be accessed by the protected application ( 2090 ), combining the public key with the modem software to produce a combined software, signing the combined software; and storing the signed combined software into the storage space ( 222 ). Other processes of manufacture, processes of operation, circuits, devices, wireless and wireline communications products, wireless handsets and systems are disclosed and claimed.