Security Architectures:

Security architectures involve novel designs of providing security by architectural changes in the medical device design. Since, devices are resource constraints, novel architectures for providing security are required that take least resources while providing considerable security levels. This field might involve either additional hardware additions/changes or changes in protocols/software.

1. Security in resource-constrained computer systems provides a good survey of what is out there in security schemes for resource-constraint embedded systems.
    
2. Block Cipher Based Security for Severely Resource-constrained Implantable Medical Devices approach is summarized below:
• Two new protocols are suggested with the experimental setup of Artificial Accommodation System (micromechatronic lens).
• First: Stream mode: Quick command communication and continuous exchange of sensor data between IMDs, with basic security.
• Second: Session mode: Cipher block chaining and challenge response scheme are utilized for higher security to send sensitive information.
  
3. The Design space of Ultra-low Energy Asymmetric Cryptography is mostly an architecture heavy paper that will require a computer architecture background to fully understand their new architecture they propose. Simplifying their approach: 
• Three different architecture proposed for low energy asymmetric cryptography. As we know asymmetric cryptography has been at the backseat because of its intense operations.  
• One with a baseline processor, next the processor with instruction set changes and third a special added processor accelerating the baseline. Implying greater security demands special purpose hardware.