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The future of cybersecurity is in the hands of hardware engineers, reports IEEE Spectrum. According to Scott Borg, director of the U.S. Cyber Consequences Unit, hackers are increasingly focusing on hardware, not on software. Initially, hackers "focused on operations control, monitoring different locations from a central site. Then they moved to process control, including programmable logic controllers and local networks. Then they migrated to embedded devices and the ability to control individual pieces of equipment. Now they are migrating to the actual sensors[...]”
The issue with computer science is that through decades of abstraction, few people understand what is happening inside the hardware. Everyone is in love with the latest apps, but the hardware is taken for granted.
A system is only as good as its weakest link. No matter how secure we design the 10th level in our software architecture, the system can be compromised if level 0, the hardware, is insecure.
The Australian Digital Technologies Curriculum has a thread on Digital Systems where students explore hardware components, peripheral devices, how systems connect to transfer data and how this can be done securely. So there is an envelope in which hardware and security can be explored in depth.
The reason we developed the Blueberry4™ educational microprocessor is for students can get an understanding of the inner workings of the machine. And yes, we have designed it so that students can hack into it and learn about attack vectors. When you know how to hack you know what countermeasures can be taken. Knowing about the hardware in detail fundamentally helps students to write software that is less prone to cyber attacks.
Let's assume for a moment that the transistor had never been invented and humankind were still using electromechanical relays, like in the early 1900's. We can still apply boolean logic to them, just as we can apply it to transistors, but what about the engineering side of things? Let's take a look:
Mechanical parts are larger, consume more electricity and wear more quickly than semiconductors.
Modern processors consist of billions of transistors. Let’s assume we had a 1 billion transistor chip and we wanted to build it with relays. If each transistor were to be replaced with one relay, then we would require 1 billion relays. Let’s further assume that 1 relay would require 1cm^3 (the size of a sugar cube) of space and that we need another 1cm^3 of space around each relay for wiring, cooling, etc. So we'd need 2cm^3 of space per relay. That would be 2 billion cm^3. for all our 1 billion relays. That’s 2,000,000,000 cm^3 = 2,000 m^3, a cube with a side length of 12.6m, equivalent to a 4 storey building. Ok, that's BIG.
What about powering these 1 billion relays?
If each relay required 50mA of current at 5V, then we’d need 50mA*1,000,000,000=50,000,000A.
50,000,000A*5V=250,000,000W, which is 250 Mega Watt. A smaller coal fired power plant produces 500 megawatt of electricity and burns 1.4 million tons of coal each year. We’d need half of this.
In summary: If we could build such a relays computer, it would be the size of a 4 storey house, require half a coal-fired power plant and consume 700,000 tons of coal each year. This would be a tad too big to carry around with us. Not to mention the heat that the 700,000 tons of coal generate.
I'm glad the transistor got invented :-)
Timing plays an important role in the proper function of a computer’s internal and external communication. When we press the Enter button on the Program Counter (which triggers a clock signal), a sequence of events takes place that we have documented in the following little video. This, and more, happens a billion times in our computers and smartphones every single second. So let's see what is going on inside the machine when we compute 5+4-2.
