Isn’t it still possible for the voter to not cast this ballot paper and bring it to the coercer who waits outside? Then the coercer fill this ballot and ask the next voter to cast it and bring back a blank ballot paper?
It seems you mean something simailar to Selene voting system where a tally board is published containing tracker vote pairs. Each voter can decrypt their tracker once the voting phase closes to check the vote and also means to fake the decryption for claiming another other tracker from the tally board as yours.
> This can easily solved be done via letting people forge receipts. Then anyone can forge a vote to give to someone offering to buy them.
This is the literal definition of receipt freeness. It’s hard to ensure that the receipt you receive to verify your vote had not already been forged by the malware.
> It’s difficult to make an E2E-VIV checking app that’s both trustworthy and receipt-free. The best solutions known allow checking only of votes that will be discarded, and casting of votes that haven’t been checked; this is highly counterintuitive for most voters!
Actually, Benaloh's challenge also does not offer receipt freeness. The adversarial strategy in such a model is to outsource the challenger itself in a hash function which decides whether to accept or discard the vote. It may look impractical at first, but one can build an app that could do that efficiently.
It can be said that all existing end-to-end verifiable remote e-voting systems compromise individual verifiability when reconciling it with receipt-freeness by introducing an assumption about the hardware-based protection of voters' secrets. If they leak or are predetermined by a corrupt vendor implementation, the malware on the voter's client can manipulate the vote at submission, and the adversary later fakes verification for the voter by exploiting that knowledge.
Still, I believe it's a solvable problem which needs more attention. Bingo evoting system is almost there, for instance, with verifiably random generated trackers, but needs a voting booth with a Bingo machine taken at home.
> However dumping that much debt all at once would require the sellers to heavily discount a large portion of their bonds, earning them increasingly fewer, and paying in (depreciating) dollars.
I think all investors are now looking at this with this foresight. Being the first to dump seems to be the winning game here.
>I think all investors are now looking at this with this foresight. Being the first to dump seems to be the winning game here.
When you're talking about hundreds of billions of dollars worth of bonds you simply can't move that much in one go. That's an elephant-in-the-bathtub situation where your moves disturb the market because of their size.
Even the first entity to dump would still have to discount a lot of their bonds. Nobody on the bond market is going to make a $200B snap purchase.
When I did my BSc and MSc in physics almost all my exams were oral just like you described. Latter I did a PhD in a different university where oral exams were never practiced. My PhD supervisor told me that part of it is because of the scaling issue, but another very interesting point he made is that it is about cultural interpretation of fairness.
In my BSc and MSc we were all basically locals who are in all aspects about the same except from the aptitude to study. In the university where I did my PhD there were much more divisions (aka diversity) in which every oral examiner would need to navigate so one group does not feel to be made preferential over another.
Having demonstrated error correction, some incremental improvements can now be made to make it more repeatable and with better characteristics.
The hard problem then remains how to connect those qubits at scale. Using a coaxial cable for each qubit is impractical; some form of multiplexing is needed. This, in turn, causes qubits to decohere while waiting for their control signal.
From analytical arguments considering a rather generic error type, we already know that for the Shor algorithm to produce a useful result, the error rate with the number of logical qubits needs to decrease as ~n^(-1/3), where `n` is the number of bits in the number [1].
This estimate, however, assumes that interaction can be turned on between arbitrary two qubits. In practice, we can only do nearest-neighbour interactions on a square lattice, and we need to simulate the interaction between two arbitrary qubits by repeated application of SWAP gates, mangling the interaction through as in the 15th puzzle. This two-qubit simulation would add about `n` SWAP gates, which would then multiply the noise factor by the same factor, hence now we need an error rate for logical qubits on a square lattice to be around ~n^(-4/3)
Now comes the error correction. The estimates are somewhat hard to make here, as they depend on the sensitivity of the readout mechanism, but for example let’s say a 10-bit number can be factored with a logical qubit error rate of 10^{-5}. Then we apply a surface code that scales exponentially, reducing the error rate by 10 times with 10 physical qubits, which we could express as ~1/10^{m/10}, where m is the number of physical qubits (which is rather optimistic). Putting in the numbers, it would follow that we need 40 physical qubits for a logical qubit, hence in total 400k physical qubits.
That may sound reasonable, but then we made the assumption that while manipulating the individual physical qubits, decoherence for each individual qubit does not happen while they are waiting for their turn. This, in fact, scales poorly with the number of qubits on the chip because physical constraints limit the number of coaxial cables that can be attached, hence multiplexing of control signals and hence the waiting of the qubits is imminent. This waiting is even more pronounced in the quantum computer cluster proposals that tend to surface sometimes.
I have also fallen in this trap by thinking that a good product that addresses the needs of users would make it wanted. But coming so far with no traction to show I seriously doubt my prospects of bridging the gap between from the needs to the wants.
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