Old Strategies.
What both recent side channel attacks have shown us is that a 'secret' encryption technique rather than a peer reviewed one is a much easier target for to side channel attacks. In both the smartcard and the keyless entry system what was discovered was the weakness in the underlying cryptography.
It is always going to be seriously hard work to prevent people with physical access to your devices, unlimited time, high resolution scopes, JTAG dongles and microscopes from getting the inside scoop on your security through obscurity techniques. Better surely to design using peer reviewed cryptographically strong systems that don't allow you to reverse engineer the master key from any reader?
