It's only feasible to block RF inside of an enclosed area... you can't feasibly block an entire RF signal that is outdoors. You could potentially jam it by flooding the airwaves with a stronger signal, but such jamming would be still be detected at the receiving end as a loss of signal, or a DOS attack.
As for how to measure latency, well... you could design the fiber so that certain parts of the signal are always reflected back, and the latency can be measured that way, and design the overall communications protocol to utilize only the unreflected portions. If the MitM tries to read the signal that is supposed to be reflected instead of simply reflecting it with the intent of retransmitting it back with the expected latency, then it can be detected the same way any eavesdropper could be otherwise detected on a quantum encrypted data line. If the MitM simply reflects the signal the same way the intended recipient would, then the latency delay will not be right because the length of fiber between the MitM and the sender will not generally be the same as the known length of fiber between the sender and recipient. If the MitM tries to artificially lengthen the fiber, then the total transmission time between the source and destination is going to be longer, and the times that each side records for different events will be different, which can be detected based on the OOB communication. The OOB radio communication can easily be listened to by any third party, but is not useful in decrypting the data that was on the fiber, only useful in verifying its authenticity.
The MitM would have to compromise either the area immediately around the transmitter or the area immediately around the receiver, both of which could be inside of secure facilities in order to have any success at blocking the signal from being received.
So now we are moving away from quantum crypto and on to measuring propagation delay
Well yes... but there's nothing absolutely nothing secret about the speed of light.
If a MitM doesn't relay the communication to the intended recipient at all, as you suggest, then the intended recipient would notice immediately that they aren't receiving expected data... and if the latency on the data is wrong, perhaps synced to an atomic clock feed on an unencrypted OOB radio channel, then they would know that the transmission was being intercepted. By virtue of being OTA, the side channel communication is immune to any MitM interception, and if the transmission of the OOB data itself is delayed by no less than the expected latency of the fibre, it cannot be utilized to fake the expected latency by the MitM attacker, because by the time they receive it, too much time has gone by to accurately fake the latency period on the fibre.
Of course, as I said... this does assume that the source and destination endpoints have been secured, and for authentication, it would require a second reliable, but itself not necessarily encrypted, communication system exists alongside it, but using radio instead of fibre to prevent a MitM attack of it as well.
You are certainly correct in that nobody else is eavesdropping on the data exchange between you and Malice... but umm... your now owned and all of your super secret secrets are compromised anyway because you were talking to the WRONG PERSON and you had NO WAY of knowing it.
Not true... you can verify latency along the line and the other side. You know exactly how long the fiber is, and the propogation velocity of light in the fiber is well known, so it would be impacted significantly by any MitM attack. If an MitM tried to fake the latency signal to make it look like you were still talking on an uncompromised line, it would be different from what an atomic clock was measuring for the actual delay because of the different total distance that the signal was travelling.
If you draw a box big enough to encompass the full length of the wire and declare everything within the box to be physically secure and trustworthy there is no point in deploying quantum crypto or any crypto
Obviously, but if only the endpoints are trustworthy (which can easily be the case, especially if the distance is more than a km or so.), and you cannot vouch for who else might be listening in. quantum crypto provides the assurance that nobody else is eavesdropping while you exchange data.
If your wage isn't high enough to meet your essential needs (food, shelter), and your obligations to the job do not leave you sufficient time to seek additional income opportunities, there is exactly zero difference in the long run between being paid a dollar an hour and working for no compensation at all.
In the long run, the only time being underpaid is better than nothing at all is when you can either still (however barely) meet your own needs with the pay, or else your job obligation leaves you enough time when you are not working to have additional sources of income.
No... because the reasons why it is irreproducible are well known and defined by quite well understood physical laws. There is no obscurity involved, at any level.
Seriously, they always knew that this would be far more practical in terms of power and efficiency for silicon based circuits than putting everything on a flat die. The reason they didn't do so wasn't because they didn't know it would be any better, it was because it wasn't really feasible from a cost-gain perspective.
I asked my shop teacher in school during an section on electronics about this back in the 1980's, and he told me back then that the only reason they didn't already make 3d integrated circuits isn't because we can't really do it , but because the technology to do it properly was typically prohibitively expensive for mass production, but even then, there was no theoretical reason it couldn't be done if money was no object.
As technology improved, the cost came down, I guess. I'm not surprised.
If you are going to assert that a comment is factually incorrect without even claiming to be aware of the context in which it was said, be aware that such a claim is very liable to have little to no resemblance to reality.
Quantum crypto only requires secrets to be kept if you need to authenticate... Which is not inherently necessary for cryptography... for example, in a secured point to point fiber connection, which in the case of quantum crypto is impossible to eavesdrop on without alerting the parties involved.
I was under the impression we were talking about security, not authentication. Authentication mechanisms might require secrets (eg, passwords, etc), but they still depend on good security systems underneath them to be reliable, and while many security systems by themselves might depend on hidden or obscured knowledge, it is not an inherent property in security in general. Sometimes the laws of physics themselves can provide all of the security that is or sometimes could possibly be imagined.
I was under the impression that we were talking about iphones here... which still need to be woken up to use, even if you don't have fingerprint detection on.
Is your objection that Apple has put the home button on the front of the device in the first place?
So, to crack the phone, one would have to disable auto-deletion of data due to failed attempts. To do this, a security research group would need to dissolve the casing of a single CPU....
The solution to that is obvious.... implement a light-sensor switch in the hardware that considers any opening of the case, unless it has previously been expressly authorized, to be equivalent to having failed to enter the correct password after whatever limited number of failed attempts are defined before auto-deletion.
That's fine... the OS can be written to disallow an arbitrary user from being able to access the interface via software. Root or admin user should still be able freely use the API as it is designed.
If an otherwise unauthorized person somehow gets root/admin privileges, then... well... you were boned already.
As you need to press the home button on the front to awaken the device in the first place, what is the difference between doing that and having the fingerprint recognizer there?
Of course, but legally you can, without anything special happening, be compelled to surrender your fingerprints to authorities for any investigation that they deem appropriate, even if you have not been personally convicted of any crime, or even if no crime has actually even occurred. Legally compelling you to surrender your pass code requires going to court first, where you at least have a chance of having a sympathetic judge.
Actually, the very essence of a null hypothesis demands falsifiable... a null hypothesis can always be disproven with a single counterexample. For example, a null hypothesis might be there are no elephants in my deep freezer. Finding a single elephant in my freezer would disprove the hypothesis, so the null statement is definitely falsifiable.
Suggesting there is no hell, however, is not really falsifiable because the notion of hell, being no less abstractly defined than god, would not necessarily need to exist in a place or time that we can observe, and is thus immune to the every conceivable attempt to disprove it. It is isomorphically equivalent to saying that outside of the observable universe, nothing at all exists, which may very well be the case, but no self respecting scientist would ever claim it as anything more than the hypothesis that it is, and would never assert it as fact simply because it can't possibly ever be refuted.
Some benefits ARE taxable - the ones where the business gives cash or a cash equivalent are still counted as income
Of course... but also, for example, is a single free small sandwich that a minimum-wage employee might get per day if they work in a kitchen truck. It costs the company only a few cents per day, but the retail price on the same sandwich would probably be two or three bucks. Over the course of the year, that could amount to hundreds of dollars in taxable benefits that could quite easily be on par with what a person would pay in subscription rates for a parking spot near where they work.
The kilogram and kilogram-force are different units, even if the latter often gets lazily abbreviated in name to the former
That is true, yes. It would be more correct for me to say that the *names* of the units are the same than it to just say (as I had) that the units are the same, but for some reason I didn't think of putting it that way when I was responding, above.
As for Newton having nothing to do with how the kilogram came to be defined today, I know that Newton actually used imperial units. The kilogram-force unit is basically just a metric equivalent to the notion of the concept of pounds of force, which would have actually been the primary expression for the notion of force prior to Newton (long before it was understood that force was actually the product of acceleration and mass, and not just the mass). The creation of the SI unit called a Newton deprecated the notion of using a weight/mass unit to describe force entirely, but the reference to the force experienced by a given mass at 1G persisted, and is still frequently used because it is often more intuitively understood by people without a physics background.
So the expression "kilograms of force" always explicitly refers to the kilogram-force unit, but it is redundant to say that so many kilograms-force of force were used to do work XYZ, so the 'force' suffix on the unit is often dropped from the unit name itself. Since the word appears almost immediately afterwards anyways, no ambiguity about the term's usage remains, but when you see "pounds of force" or "kilograms of force", the actual units being measured to are pound-force and kilogram-force.
Mass is, in fact, measured in kg. It has the same unit as what is used for weight, but outside of the environment of earth, they are not the same thing.
As you said. mass is constant and weight will vary. That doesn't mean I'm not still 85kg if I go to the moon. I will only weigh about 14kg there, but my mass is still the same. Weight is a measurement of force that depends on the environment, and mass is a measurement of inertia, which is considered an intrinsic property of matter. Nonetheless the units are the same, because prior to the discovery of inertia by Newton, mass and weight were always thought of as the same thing
Kilograms are not just units of mass. They are also units of weight, which itself is a measurement of force. Each kilogram of force is actually equivalent to 9.8 Newtons of force.
Actually, now that employee discounts are considered a taxable benefit here, that's probably not so cut and dried anymore. If somebody is getting a discount on their tuition, the difference between the price they pay and the regular tuition price is a taxable benefit that they have to pay income tax on. The federal government is saying that employee discounts won't really be taxed, but that's not what the CRA guidelines said.
Slashdot Mirror
It's only feasible to block RF inside of an enclosed area... you can't feasibly block an entire RF signal that is outdoors. You could potentially jam it by flooding the airwaves with a stronger signal, but such jamming would be still be detected at the receiving end as a loss of signal, or a DOS attack.
As for how to measure latency, well... you could design the fiber so that certain parts of the signal are always reflected back, and the latency can be measured that way, and design the overall communications protocol to utilize only the unreflected portions. If the MitM tries to read the signal that is supposed to be reflected instead of simply reflecting it with the intent of retransmitting it back with the expected latency, then it can be detected the same way any eavesdropper could be otherwise detected on a quantum encrypted data line. If the MitM simply reflects the signal the same way the intended recipient would, then the latency delay will not be right because the length of fiber between the MitM and the sender will not generally be the same as the known length of fiber between the sender and recipient. If the MitM tries to artificially lengthen the fiber, then the total transmission time between the source and destination is going to be longer, and the times that each side records for different events will be different, which can be detected based on the OOB communication. The OOB radio communication can easily be listened to by any third party, but is not useful in decrypting the data that was on the fiber, only useful in verifying its authenticity.
The MitM would have to compromise either the area immediately around the transmitter or the area immediately around the receiver, both of which could be inside of secure facilities in order to have any success at blocking the signal from being received.
Well yes... but there's nothing absolutely nothing secret about the speed of light.
If a MitM doesn't relay the communication to the intended recipient at all, as you suggest, then the intended recipient would notice immediately that they aren't receiving expected data... and if the latency on the data is wrong, perhaps synced to an atomic clock feed on an unencrypted OOB radio channel, then they would know that the transmission was being intercepted. By virtue of being OTA, the side channel communication is immune to any MitM interception, and if the transmission of the OOB data itself is delayed by no less than the expected latency of the fibre, it cannot be utilized to fake the expected latency by the MitM attacker, because by the time they receive it, too much time has gone by to accurately fake the latency period on the fibre.
Of course, as I said... this does assume that the source and destination endpoints have been secured, and for authentication, it would require a second reliable, but itself not necessarily encrypted, communication system exists alongside it, but using radio instead of fibre to prevent a MitM attack of it as well.
Not true... you can verify latency along the line and the other side. You know exactly how long the fiber is, and the propogation velocity of light in the fiber is well known, so it would be impacted significantly by any MitM attack. If an MitM tried to fake the latency signal to make it look like you were still talking on an uncompromised line, it would be different from what an atomic clock was measuring for the actual delay because of the different total distance that the signal was travelling.
Obviously, but if only the endpoints are trustworthy (which can easily be the case, especially if the distance is more than a km or so.), and you cannot vouch for who else might be listening in. quantum crypto provides the assurance that nobody else is eavesdropping while you exchange data.
If your wage isn't high enough to meet your essential needs (food, shelter), and your obligations to the job do not leave you sufficient time to seek additional income opportunities, there is exactly zero difference in the long run between being paid a dollar an hour and working for no compensation at all.
In the long run, the only time being underpaid is better than nothing at all is when you can either still (however barely) meet your own needs with the pay, or else your job obligation leaves you enough time when you are not working to have additional sources of income.
No... because the reasons why it is irreproducible are well known and defined by quite well understood physical laws. There is no obscurity involved, at any level.
Seriously, they always knew that this would be far more practical in terms of power and efficiency for silicon based circuits than putting everything on a flat die. The reason they didn't do so wasn't because they didn't know it would be any better, it was because it wasn't really feasible from a cost-gain perspective.
I asked my shop teacher in school during an section on electronics about this back in the 1980's, and he told me back then that the only reason they didn't already make 3d integrated circuits isn't because we can't really do it , but because the technology to do it properly was typically prohibitively expensive for mass production, but even then, there was no theoretical reason it couldn't be done if money was no object.
As technology improved, the cost came down, I guess. I'm not surprised.
Sure, but you could do the same thing with google or any search engine.
Or, apparently, the post topic:
But that's irrelevant.
If you are going to assert that a comment is factually incorrect without even claiming to be aware of the context in which it was said, be aware that such a claim is very liable to have little to no resemblance to reality.
Quantum crypto only requires secrets to be kept if you need to authenticate... Which is not inherently necessary for cryptography... for example, in a secured point to point fiber connection, which in the case of quantum crypto is impossible to eavesdrop on without alerting the parties involved.
I was under the impression we were talking about security, not authentication. Authentication mechanisms might require secrets (eg, passwords, etc), but they still depend on good security systems underneath them to be reliable, and while many security systems by themselves might depend on hidden or obscured knowledge, it is not an inherent property in security in general. Sometimes the laws of physics themselves can provide all of the security that is or sometimes could possibly be imagined.
The security of quantum cryptography does not depend on obscured information, but from the property of unreproducibility
I was under the impression that we were talking about iphones here... which still need to be woken up to use, even if you don't have fingerprint detection on.
Is your objection that Apple has put the home button on the front of the device in the first place?
The solution to that is obvious.... implement a light-sensor switch in the hardware that considers any opening of the case, unless it has previously been expressly authorized, to be equivalent to having failed to enter the correct password after whatever limited number of failed attempts are defined before auto-deletion.
That's fine... the OS can be written to disallow an arbitrary user from being able to access the interface via software. Root or admin user should still be able freely use the API as it is designed.
If an otherwise unauthorized person somehow gets root/admin privileges, then... well... you were boned already.
How in the world can DuckDuckGo plausibly claim not to track you when they have a settings system that persists between visits?
As you need to press the home button on the front to awaken the device in the first place, what is the difference between doing that and having the fingerprint recognizer there?
Of course, but legally you can, without anything special happening, be compelled to surrender your fingerprints to authorities for any investigation that they deem appropriate, even if you have not been personally convicted of any crime, or even if no crime has actually even occurred. Legally compelling you to surrender your pass code requires going to court first, where you at least have a chance of having a sympathetic judge.
Actually, the very essence of a null hypothesis demands falsifiable... a null hypothesis can always be disproven with a single counterexample. For example, a null hypothesis might be there are no elephants in my deep freezer. Finding a single elephant in my freezer would disprove the hypothesis, so the null statement is definitely falsifiable. Suggesting there is no hell, however, is not really falsifiable because the notion of hell, being no less abstractly defined than god, would not necessarily need to exist in a place or time that we can observe, and is thus immune to the every conceivable attempt to disprove it. It is isomorphically equivalent to saying that outside of the observable universe, nothing at all exists, which may very well be the case, but no self respecting scientist would ever claim it as anything more than the hypothesis that it is, and would never assert it as fact simply because it can't possibly ever be refuted.
.... we start claiming we can predict earthquakes like we claim to be able to predict the weather or the climate?
You may be right, but such a statement is not any less unfalsifiable than the notion that god exists in the first place.
Of course... but also, for example, is a single free small sandwich that a minimum-wage employee might get per day if they work in a kitchen truck. It costs the company only a few cents per day, but the retail price on the same sandwich would probably be two or three bucks. Over the course of the year, that could amount to hundreds of dollars in taxable benefits that could quite easily be on par with what a person would pay in subscription rates for a parking spot near where they work.
That is true, yes. It would be more correct for me to say that the *names* of the units are the same than it to just say (as I had) that the units are the same, but for some reason I didn't think of putting it that way when I was responding, above.
As for Newton having nothing to do with how the kilogram came to be defined today, I know that Newton actually used imperial units. The kilogram-force unit is basically just a metric equivalent to the notion of the concept of pounds of force, which would have actually been the primary expression for the notion of force prior to Newton (long before it was understood that force was actually the product of acceleration and mass, and not just the mass). The creation of the SI unit called a Newton deprecated the notion of using a weight/mass unit to describe force entirely, but the reference to the force experienced by a given mass at 1G persisted, and is still frequently used because it is often more intuitively understood by people without a physics background.
So the expression "kilograms of force" always explicitly refers to the kilogram-force unit, but it is redundant to say that so many kilograms-force of force were used to do work XYZ, so the 'force' suffix on the unit is often dropped from the unit name itself. Since the word appears almost immediately afterwards anyways, no ambiguity about the term's usage remains, but when you see "pounds of force" or "kilograms of force", the actual units being measured to are pound-force and kilogram-force.
Mass is, in fact, measured in kg. It has the same unit as what is used for weight, but outside of the environment of earth, they are not the same thing.
As you said. mass is constant and weight will vary. That doesn't mean I'm not still 85kg if I go to the moon. I will only weigh about 14kg there, but my mass is still the same. Weight is a measurement of force that depends on the environment, and mass is a measurement of inertia, which is considered an intrinsic property of matter. Nonetheless the units are the same, because prior to the discovery of inertia by Newton, mass and weight were always thought of as the same thing
Kilograms are not just units of mass. They are also units of weight, which itself is a measurement of force. Each kilogram of force is actually equivalent to 9.8 Newtons of force.
It's really that simple.
Actually, now that employee discounts are considered a taxable benefit here, that's probably not so cut and dried anymore. If somebody is getting a discount on their tuition, the difference between the price they pay and the regular tuition price is a taxable benefit that they have to pay income tax on. The federal government is saying that employee discounts won't really be taxed, but that's not what the CRA guidelines said.