Jon Roland
2014-08-14 15:05:52 UTC
We happily use public-key crypto tools every day, but we use them on computers. So I pose this question to anyone on the forum who might be able to answer.
Suppose we want bright people equipped only with pencils, paper, and an abacus to manually generate a 2048-bit key pair and encrypt a 10KB message using one of the keys. How long might it take to do that? Hours, days, weeks, months, years?
Now suppose the sender does not provide the receiver with the complete key, but omits parts of it, those parts to be generated from data observed in a future event he knows will happen on a date certain, but which cannot be predicted, as a way to make sure the message is not decrypted before that future event.
The receiver would also not have a computer to do the decryption, especially not quantum computers to crack it even without the missing parts.
In effect, the message is a time capsule that can't be opened prematurely, even if future recipients get computers.
If you suspect I am researching for a science fiction story, you are correct.
Any help would be appreciated.
I should further explain. The enterprise is directed by a person from the future who knows the celestial events that provide the data to generate the missing parts of the key. Perhaps the celestial coordinates of the seven brightest objects surrounding a nova. So the method of generating the missing parts is set at the outset, and the events occur hundreds of years after the original message is encrypted.
Think about how a visitor from the future to a medieval past would set a chain of events in motion, but need to prompt future generations with messages to keep them on a track to deal with some distant future catastrophe that they would need the information to avoid. The visitor has only one chance to guide history despite any loss of faith or direction that successors of the original senders of the message might undergo. He can't just provide them all the direction at once, because after some generations it would no longer be credible, or attacked as witchcraft. (Nostradamus encoded his predictions for a reason, but not as usefully as he might have done.) So the visitor reinforces the guidance with several messages about lesser but important disasters and how to prepare for them, to be revealed just before they occur, but in time to prepare. (E.g., eruption of Yellowstone, tsunami caused by collapse of La Palma, etc.) Each revelation rebuilds confidence in the reliability of the next ones, and thus political support for the sacrifices that need to be made to prepare.
So I need to know whether such cryptography is feasible without computers.
Suppose we want bright people equipped only with pencils, paper, and an abacus to manually generate a 2048-bit key pair and encrypt a 10KB message using one of the keys. How long might it take to do that? Hours, days, weeks, months, years?
Now suppose the sender does not provide the receiver with the complete key, but omits parts of it, those parts to be generated from data observed in a future event he knows will happen on a date certain, but which cannot be predicted, as a way to make sure the message is not decrypted before that future event.
The receiver would also not have a computer to do the decryption, especially not quantum computers to crack it even without the missing parts.
In effect, the message is a time capsule that can't be opened prematurely, even if future recipients get computers.
If you suspect I am researching for a science fiction story, you are correct.
Any help would be appreciated.
I should further explain. The enterprise is directed by a person from the future who knows the celestial events that provide the data to generate the missing parts of the key. Perhaps the celestial coordinates of the seven brightest objects surrounding a nova. So the method of generating the missing parts is set at the outset, and the events occur hundreds of years after the original message is encrypted.
Think about how a visitor from the future to a medieval past would set a chain of events in motion, but need to prompt future generations with messages to keep them on a track to deal with some distant future catastrophe that they would need the information to avoid. The visitor has only one chance to guide history despite any loss of faith or direction that successors of the original senders of the message might undergo. He can't just provide them all the direction at once, because after some generations it would no longer be credible, or attacked as witchcraft. (Nostradamus encoded his predictions for a reason, but not as usefully as he might have done.) So the visitor reinforces the guidance with several messages about lesser but important disasters and how to prepare for them, to be revealed just before they occur, but in time to prepare. (E.g., eruption of Yellowstone, tsunami caused by collapse of La Palma, etc.) Each revelation rebuilds confidence in the reliability of the next ones, and thus political support for the sacrifices that need to be made to prepare.
So I need to know whether such cryptography is feasible without computers.