I work with a guy who is an expert in radioactivity and radiation protection. So we just sat down with him to calculate how much polonium-210 is lethal to a human being. It turns out to be less than a fraction of a miligramm. Some people say on this post that alpha radiation can not penetrate skin thus it is not very dangerous. Unfortunately it is not so. If it goes inside as a part of soluable substance than it gets inside your tissues, blood, organs and damages everything around.
One way to think about radiation damage is the following: Single decay of an Polonium atom carries about million times more energy than chemical transormation of a single molecule in explosives. So one milligram of polonium is roughly equivalent to 1 kilo of explosives. If you swallow 1 kilo of dynamite and it would explode inside - than you are very unlikey to survive. After all 5 grams of explosives are enough to accelerate a bullet. Experts would probably criticise me for such comparison, and they are right, but still it gives you some feeling of damage that radiation will do to your body.
What worries me a lot in this story are traces of polonium. It is very easy to contain alpha sources as they are usually in hermetic ampules and can not be traced at all. So I see several reasons.
First is that police is lying or misinterpreting the results. It seems unlikey with the growing amout of evidence, though I can not excude it.
The second explanation is that there is one or several human beings who do not know that they carry polonium inside them and polonium leaks out of their bodies with sweat and other human liquids. But calculations show that they had to swallow lethal amounts.
The third one is that traces are done on purpose
The forth is that the killer was so unprofessional that he made spills all over the place.
My take on this story is that it is VERY strange. Very unprofessional, very public-oriented, very anti-russian. My prediction is that the whole story soon will be shut tight: no information leaks, no interviews, nothing - and there will be reason to that - real plot will be uncovered, with some dirty unpleasant stories behind it, which would have nothing to do with politics or russian secret services.
Re:Not a problem (a way to sign messages)
on
SHA-1 Broken
·
· Score: 1
There is also a protection against attacks on digital signatures that uses birthday party paradox trick. Right before signing the message you ADD some arbitrary text at the end of the message and AFTER THAT algorithm calculates hash and signature. So if someone prepared 2 texts that give same hash and hence same digital signature, now they lost there tremendous amount of preparation work.
Pretty much the same idea is in salt. Though here you add salt at the very last minute.
"Building the quantum network" discusses possibility to use Trusted relay to transmit key over large distances (currently 50km). But would not the mere existance of such a device mean that one can intercept the message and quickly dump the copy back into the network. Then the only question would be how quickly you can technically do it (They probably synchronize clocks and transmit time in the message). If you can do it quickly enough (there is no PHYSICS law to limit that AFAIK) then the whole scheme fails.
Slashdot Mirror
I work with a guy who is an expert in radioactivity and radiation protection. So we just sat down with him to calculate how much polonium-210 is lethal to a human being. It turns out to be less than a fraction of a miligramm. Some people say on this post that alpha radiation can not penetrate skin thus it is not very dangerous. Unfortunately it is not so. If it goes inside as a part of soluable substance than it gets inside your tissues, blood, organs and damages everything around.
One way to think about radiation damage is the following: Single decay of an Polonium atom carries about million times more energy than chemical transormation of a single molecule in explosives. So one milligram of polonium is roughly equivalent to 1 kilo of explosives. If you swallow 1 kilo of dynamite and it would explode inside - than you are very unlikey to survive. After all 5 grams of explosives are enough to accelerate a bullet. Experts would probably criticise me for such comparison, and they are right, but still it gives you some feeling of damage that radiation will do to your body.
What worries me a lot in this story are traces of polonium. It is very easy to contain alpha sources as they are usually in hermetic ampules and can not be traced at all. So I see several reasons.
First is that police is lying or misinterpreting the results. It seems unlikey with the growing amout of evidence, though I can not excude it.
The second explanation is that there is one or several human beings who do not know that they carry polonium inside them and polonium leaks out of their bodies with sweat and other human liquids. But calculations show that they had to swallow lethal amounts.
The third one is that traces are done on purpose
The forth is that the killer was so unprofessional that he made spills all over the place.
My take on this story is that it is VERY strange. Very unprofessional, very public-oriented, very anti-russian. My prediction is that the whole story soon will be shut tight: no information leaks, no interviews, nothing - and there will be reason to that - real plot will be uncovered, with some dirty unpleasant stories behind it, which would have nothing to do with politics or russian secret services.
There is also a protection against attacks on digital signatures that uses birthday party paradox trick. Right before signing the message you ADD some arbitrary text at the end of the message and AFTER THAT algorithm calculates hash and signature. So if someone prepared 2 texts that give same hash and hence same digital signature, now they lost there tremendous amount of preparation work.
Pretty much the same idea is in salt. Though here you add salt at the very last minute.
"Building the quantum network" discusses possibility to use Trusted relay to transmit key over large distances (currently 50km). But would not the mere existance of such a device mean that one can intercept the message and quickly dump the copy back into the network. Then the only question would be how quickly you can technically do it (They probably synchronize clocks and transmit time in the message). If you can do it quickly enough (there is no PHYSICS law to limit that AFAIK) then the whole scheme fails.