“Unfortunately, the entire security sector is RSA-signed using a private key only Microsoft possesses.”
The Xbox 360’s 20 GB drive cost $99 at launch, when $57 bought an 80 GB drive for a PC. Sector 16 of every genuine drive holds the serial, firmware and model, signed by Microsoft, and the console refuses anything that doesn’t match. The only workaround was rewriting a Western Digital drive’s firmware to impersonate one. Microsoft used cryptography to defend a storage markup.