Cryptography Stack Exchange
Cryptography Stack Exchange

Questions tagged [timed-release]

Time-lock puzzles and other cryptographic schemes intended to ensure that a message cannot be read until a certain time has passed.

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Time Capsule cryptography?

Does there exist any cryptographic algorithm which encrypts data in such a way that it can only be decrypted after a certain period of time? The only idea that I can think of, is something like this: Seed a PRNG with a public value. Run the PRNG for…
Jake
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What is the progress on the MIT LCS35 Time Capsule Crypto-Puzzle?

Ron Rivest posed a puzzle in 1999. MIT LCS35 Time Capsule Crypto-Puzzle. The problem is to compute $2^{2^t} \pmod n$ for specified values of $t$ and $n$. Here $n$ is the product of two large primes, and $t$ is chosen to set the desired level…
DanBeale
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Is it possible to make time-locked encrytion algorithm?

I'm not sure if what I'm asking is even a valid question but here goes. Would it be possible to add a mechanism to an encryption algorithm that would mean it had to be a certain time of the day or a certain day of the year for the encryption to be…
bowy tehcTo
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Dead-Man's Switch Cryptography?

I was looking at Time Capsule cryptography? and came up wth this idea. Question: Is there a way to store a secret such that the creator must update it or the secret will be decrypted and anyone can access it? Example: I use this algorithm to encrypt…
edggy
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Time Based encryption

Looking for the language to describe a solution I am looking for... As a systems admin for an educational institution, I would like to: a) post our tests in an encrypted form b) at a certain time, make the contents available to the user (online or…
Doug Coleman
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Ways to make a "doomsday" cryptocurrency which becomes untradable

As a social experiment (not a money-making scheme), I'm interested in developing a crazy cryptocurrency which, by its very design, will become worthless and untradable after a certain point. Ideally, this would be a fixed date like "January 1st…
Chris Conlon
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Why is time-lapse cryptography not popular?

Time-Lapse Cryptography has been introduced by Michael Rabin and Christopher Thorpe in the paper “Time-Lapse Cryptography”, but it does not seems to be popular. It is a really good paper with an great theoretic background and the authors themselves…
funtime
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How would we design a fast circuit to solve LCS35?

LCS35 is a time-lock puzzle, stated in Ronald L. Rivest's Description of the LCS35 Time Capsule Crypto-Puzzle [1] (April 1999). That instantiates a system in Ronald L. Rivest, Adi Shamir and David A. Wagner's Time-Lock puzzles and timed-release…
fgrieu
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Time-locked Puzzles & Dead Man's Switch Intervention

I have been researching time-based puzzles. Specifically, computationally expensive algorithms for the purpose of a time-lock. This has lead me to sequential squaring, firstly, as well as some memory-hard approaches and of course trusted third…
xendi
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Is there a quantum-safe time lock?

Most successive squaring time lock puzzles I've seen appear to be broken by Shor's algorithm. Is there another practical and efficient time lock protocol that is not broken by Shor's algorithm? If not, what will I need to make one? time lock…
Nic
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1 answer

Time locked cryptography using Bitcoin difficulty param and/or smart contract?

Outcome: Create a message with a count down timer. Once a top level password is entered, a countdown timer starts. Once timer expires, the message is decrypted. Known methods: Proof of work. User has to use computing power to decrypt the…
Emily
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Have time-release servers been implemented?

Conceivably, Alice could release a public encryption key and promise to release the private decryption key on a certain date. That way anyone could use that encryption key, combined with others from similar services, and throw away the key so the…
Nic
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Could time lock encryption be implemented through indistinguishable obfuscation?

In the paper "How to build time-lock encryption", the authors give a theoretical solution to build time-lock encryption using multi-linear based witness encryption and blockchain. However, an instantiation of the construction is unfeasible to build…
Oiiiwk
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How can I generate a deterministic evenly distributed random number in a blockchain

Here's the hypothetical. There's a blockchain, which for the sake of simplicity, is modelled around Bitcoin and proof-of-work. My goal, is that for each mined block, rather than a set reward (12.5 BTC), each block has a deterministic reward value,…
ihatecsv
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Sequential public key generation with secret private keys?

So this is an idea that popped into my head the other day and I wonder if there are any known crytographic schemes with these properties? Is there a way to construct a public / private key system in such a way that I can somehow compute some "seed"…
monoceres
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