Not even close to secure. I haven't worked with US phones, but in Europe I can send you a SMS message that appears to be from any MSISDN (phone number). Violat

Not even close to secure. I haven't worked with US phones, but in Europe I can send you a SMS message that appears to be from any MSISDN (phone number). Violates all kinds of terms of service and contracts, but there's absolutely no technical verification of origin of standard SMS.