Cryptography Stack Exchange
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Questions tagged [inherently-sequential]

Inherently sequential is In opposition to embarrassingly parallel tasks, the execution of some tasks depends heavily on the results of others. In other words, those tasks are not independent, and thus, cannot be made parallel or concurrent. Furthermore, if we were to try to implement concurrency into those programs, it could cost us more execution time to produce the same results.

Ref:https://www.oreilly.com/library/view/mastering-concurrency-in/9781789343052/8fb7a4c0-6bcb-44fe-b72a-9bb8c0360ce9.xhtml Ref:https://en.wikipedia.org/wiki/NC_(complexity) Ref:https://www.sciencedirect.com/science/article/pii/089054019290033C/pdf?md5=9be89bc0019b46842937c40da1f0c517&pid=1-s2.0-089054019290033C-main.pdf Ref:https://www.quora.com/What-are-some-computational-problems-that-are-inherently-sequential-and-cannot-significantly-be-sped-up-by-using-parallelism

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Can Grover's algorithm be parallelized?

Grover's algorithm can search an unordered list of length $N$ in time $\sqrt{N}$ on a quantum computer. Applied to cryptography, this means that it can recover n-bit keys and find preimages for n-bit hashes with a cost of $2^{n/2}$. But the basic…
CodesInChaos
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Are there secure stream ciphers that cannot be parallelized?

Are there any stream ciphers (or a deterministic random number generators, that should work as well I guess?) that cannot be parallelized? For example, if I seed it with a specific value, and then "run" it for a year, generating more and more bits,…
Cray
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Is XOR-and-SUM inherently sequential?

I have been thinking recently about inherently sequential functions. In trying to wrap my head around them, I tried to come to the simplest possible function that looks inherently sequential to me. For didactical purposes, I'd like some…
Matteo Monti
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How quickly can we compute SHA256?

Disclaimer. I have asked a similar question on Electronics StackExchange: they advised me to try here. The question I am in the process of developing a simple protocol whose security relies on the assumption that computing the SHA256 hash of a very…
Matteo Monti
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A doubt on Proofs-of-Sequential-Work protocols

Proofs-of-Sequential-Work ($\mathsf{PoSW}$) are cryptographic protocols that engage two parties, a prover with $\mathtt{poly}(N)$-parallel processors and a deterministic verifier such that the verifier can check in $\mathcal{O}(\log{N})$-time if the…
Somudro Gupto
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