Editing 2651: Air Gap
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==Explanation== | ==Explanation== | ||
+ | {{incomplete|Created by an AIR GAP-PROTECTED BOT - Please change this comment when editing this page. Do NOT delete this tag too soon.}} | ||
+ | This is another one of [[Randall|Randall's]] [[:Category:Tips|Tips]], this time an Energy Tip. | ||
− | + | The comic [[#Context for understanding the conflation joke|conflates the concepts]] of computer network security and home electrical power safety to comical effect, resulting in a deeply impractical and ineffective proposed solution. In {{w|computer security}}, {{w|Air_gap_(networking)|air-gapping}} is a measure used to secure sensitive computers or networks of computers by isolating them from the broader internet, since computers are often breached through the internet. | |
− | [[Randall]] suggests increasing the security of your home power supply by air-gapping it, using the light from a powered lightbulb to power a solar panel which then supplies power to the home, such that there is no physical wired connection between your house and the public electricity network. This is a large and very inefficient version of an {{w|opto-isolator}}, but would protect equipment behind the solar panel from power surges such as lightning strikes (which in an improperly {{w|Ground (electricity)|grounded}} home could blow out the light bulb, but not so easily risk frying the equipment beyond the photovoltaic cell and its inverter). Due to its inefficiency, this approach would waste substantial amounts of energy. | + | [[Randall]] suggests increasing the security of your home power supply by air-gapping it, using the light from a powered lightbulb to power a solar panel which then supplies power to the home, such that there is no physical wired connection between your house and the public electricity network. This is a large and very inefficient version of an {{w|opto-isolator}}, but would protect equipment behind the solar panel from power surges such as lightning strikes (which in an improperly {{w|Ground (electricity)|grounded}} home could blow out the light bulb, but not so easily risk frying the equipment beyond the photovoltaic cell and its inverter). Due to its inefficiency, this approach would waste substantial amounts of energy. |
− | The title text mentions that a computer can still be connected to the internet via the power supply by using {{w|powerline networking}}, but that the bandwidth would be reduced by the lightbulb's warmup and cooldown delay, which would reduce the signalling rate the lightbulb could accomplish to no more than hundreds of bits per second, if that, for incandescent bulbs. However, as the | + | The title text mentions that a computer can still be connected to the internet via the power supply by using {{w|powerline networking}}, but that the bandwidth would be reduced by the lightbulb's warmup and cooldown delay, which would reduce the signalling rate the lightbulb could accomplish to no more than hundreds of bits per second, if that, for incandescent bulbs. However, as the solar panel cannot emit signals, the unidirectional link would be useless for traditional networking, because essential requests and acknowledgments would be unable to travel from behind the solar panel to the lightbulb. Early {{w|communication satellite}} systems for data networking used high-bandwidth unidirectional {{w|downlink}}s paired with low bandwidth ground telephone lines for outbound transmission, but such network configurations remain very uncommon.{{cn}} |
− | Randall's solution is of course a joke. But in reality he could have used {{w|isolation transformer}}s, which serve to allow the transfer of power via changing {{w|electromagnetic field}}s without an electrically conductive path. Most transformers, including "wall wart" power adapters, provide this form of isolation and protect devices from noise, voltage transients, most surges, and shock hazard, using fuses and other circuitry. They also limit powerline networking bandwidth by filtering out high frequencies | + | Randall's solution is of course a joke. But in reality he could have used {{w|isolation transformer}}s, which serve to allow the transfer of power via changing {{w|electromagnetic field}}s without an electrically conductive path. Most transformers, including "wall wart" power adapters, provide this form of isolation and protect devices from noise, voltage transients, most surges, and shock hazard, using fuses and other circuitry. They also limit powerline networking bandwidth by filtering out high frequencies. |
The look and subject of this comic is reminiscent of the [[:Category:Cursed Connectors|Cursed Connectors]] series. But without the numbered cursed connector in the comic, this is not one of those connectors. | The look and subject of this comic is reminiscent of the [[:Category:Cursed Connectors|Cursed Connectors]] series. But without the numbered cursed connector in the comic, this is not one of those connectors. | ||
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* Solar panels are generally around 20% efficient at converting light into electricity, with claims at the world record from a single light source at around 40%. | * Solar panels are generally around 20% efficient at converting light into electricity, with claims at the world record from a single light source at around 40%. | ||
− | All these efficiency-reducing factors, and others, multiply together. Therefore, only a small fraction of energy would be transmitted between the two ends of the air gap, making the circuit require much more electricity and be much less cost-efficient. For instance, the generous assumptions above lead to 96% of the power being lost. The solution as illustrated shows a single apparently-normal lightbulb, which | + | All these efficiency-reducing factors, and others, multiply together. Therefore, only a small fraction of energy would be transmitted between the two ends of the air gap, making the circuit require much more electricity and be much less cost-efficient. For instance, the generous assumptions above lead to 96% of the power being lost. |
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+ | The solution as illustrated shows a single apparently-normal lightbulb, the highest-powered of which usually draw under 250 watts of power. Given the above efficiency issues, it would provide less than a tenth as much power. | ||
===How this could have a theoretical benefit=== | ===How this could have a theoretical benefit=== | ||
− | + | * There are exotic situations where malware on a computer should not be able to communicate with the outside world. Electricity usage is a simple-to-use side channel which would be made much less practical by such a contraption. The power draw of the lamp would be independent of the power consumption of the device.{{Actual citation needed}} | |
− | + | ===Context for understanding the conflation joke=== | |
+ | One relatively obscure way this comic is funny involves the relationship of the two concepts being conflated. {{w|Power analysis}} in computer security is a form of {{w|side-channel attack}} where the attacker observes and/or manipulates the power use by a device for some reason — for example, to gain insight into an otherwise protected process, or to exfiltrate information without having to use a monitored network connection. Power analysis in fire safety means measuring the {{w|power factor}}, watts, resistance, inductance, capacitance, volts, and amps of electrical circuits. | ||
==Transcript== | ==Transcript== |