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Aug
28
revised DES hardware implementation of substitution lookup table [ ReWorked ]
Mention the PALCE22V10
Aug
28
revised DES hardware implementation of substitution lookup table [ ReWorked ]
clarify depth of the proposed construction
Aug
28
revised DES hardware implementation of substitution lookup table [ ReWorked ]
Explain a regularity of S-boxes, and a possible construction.
Aug
28
revised DES hardware implementation of substitution lookup table [ ReWorked ]
Introduce the 2732 - remember these?
Aug
28
answered DES hardware implementation of substitution lookup table [ ReWorked ]
Aug
27
comment Can iterated hashing be used to mitigate collision and preimage weaknesses?
@boot4life: your justification is quite different from mine, and just as based on reasonable argument rather than proof. Indeed hashing twice makes twice as many rounds, which can increase security in some contexts; on top of that there is a major irregularity in the middle of the rounds, as we finalize the first hash, pad it, and reenter it as message for the other rounds, which arguably could help preimage security too - at least we have proof that it does not doom it!
Aug
27
revised What security authorities and standards reject $e=3$ in RSA, when, and with what rationale?
Referenec to FIPS 186-4 rather than the obsolete -3
Aug
27
comment Can iterated hashing be used to mitigate collision and preimage weaknesses?
@boot4life: see added Handwaving argument
Aug
27
revised Can iterated hashing be used to mitigate collision and preimage weaknesses?
Add handwaving argument
Aug
27
awarded  Good Question
Aug
27
revised Can iterated hashing be used to mitigate collision and preimage weaknesses?
added 31 characters in body
Aug
27
revised Can iterated hashing be used to mitigate collision and preimage weaknesses?
Answer the other aspect of the question
Aug
27
revised Can iterated hashing be used to mitigate collision and preimage weaknesses?
Expand, synthetic answer.
Aug
27
answered Can iterated hashing be used to mitigate collision and preimage weaknesses?
Aug
27
comment Can RSA be securely used for “blind decryption”?
I would say that the protocol works, in the sense that if Sally is able to store $\mathcal E(k)$ and keep it secret, she can get back to $k$, thus $H(k)$, without revealing these, with the help of Charlie; further, verifying what Charlie returns, which is easy, prevents an active adversary from messing with the recovered $k$. $\;$ However I fail to see why the server does not keep $k$ or $H(k)$ rather than $\mathcal E(k)$; if we assume Charlie does its task without any check or limit in time, that seems to achieve the same result, in a much simpler way.
Aug
27
comment Can RSA be securely used for “blind decryption”?
The part about Charlie not revealing "anything equivalent to Ki" does not seem so much of a problem to me: although we do not have a proof of that, it is widely accepted that in textbook RSA, temporary access to a decryption oracle can not allows extraction of a private key, or otherwise help the decryption of random messages drawn after access to the decryption oracle has stopped.
Aug
26
awarded  Enlightened
Aug
26
comment Can RSA be securely used for “blind decryption”?
Some notes: It seems the server must store the client's public key in integrity-trusted storage, and $\mathcal E(k)$ in integrity+confidentiality-trusted storage, despite the last sentence in second bullet. $\;$ The client seems to need to know $H(k)$, and it is not told how; that part of the exchange might interfere with the rest.
Aug
26
awarded  Nice Answer
Aug
26
revised How feasible would it be to generate 300 million public key pairs in 8 hours?
polish