Questions tagged [hash-based]
7 questions
3
votes
1 answer
SHA3-256 vs SHAKE256_256 in XMSS and SPHINCS
By SHAKE256_256, I mean taking first 256 bits of the output of SHAKE256
i.e. SHAKE256_256(M) = SHAKE256(M,256)
What is the motivation of choosing SHAKE256_256 instead of SHA3-256 in XMSS and SPHINCS. Are there any advantages of SHAKE256_256 over…
user
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2
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3 answers
What are some use cases for signature scheme that can only sign finite amount of time?
From one-time hash-based signature, one can convert it into 2^d time signature by using Merkle hash tree.
However, it seems to be a trick that enables multi-time signing.
My question is:
is there any use case for a signature scheme that can only be…
DiamondDuck
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2
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0 answers
Hash-based public-key cryptography
Over the years, new discoveries have weakened some of the mathematical primitives used in cryptography, like the broken Knapsack cryptosystem, Shor's post-quantum algorithm, etc. What we believe to be hard problems today, can become simpler…
Jason Smith
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2
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1 answer
How does signing with FORS work in SPHINCS+?
I was reading the SPHINCS+ paper and got confused in the signing with FORS (forest of random subsets) part.
I understand how we can sign a message using FORS but I couldn't understand how we choose the corresponding WOTS+ key to sign the FORS root…
Andrew
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0
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How can I call a recursively defined operator from another operator in EasyCrypt?
I'm implementing parts of SHA-256 in EasyCrypt and need to define a power function (pow) that I can call from within other operator definitions (such as for logical shift operations). However, when I try to call my recursively defined pow operator,…
m Amiri
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0
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1 answer
How come we only need to generate the first tree in each layer in XMSS MT
From what I understand, to reduce the time taken for public key generation, you can use nested trees in XMSS to form Multi-tree XMSS.
For an instantion of 2 layers, it seems that the leaf of each L tree (one of these nested trees) is an OTS public…
João Diogo Duarte
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