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| bio | website | vyznev.net |
|---|---|---|
| location | Helsinki, Finland | |
| age | ||
| visits | member for | 1 year, 9 months |
| seen | May 12 at 7:27 | |
| stats | profile views | 90 |
I'm not really a cryptographer, I just play one on the internet.
Seriously, I'm just a programmer and mathematician interested in puzzles and information security. I don't have any kind of formal crypto training, but I've picked up a few things here and there over the years. Topics I'm particularly interested in include protocol design and analysis, classical ciphers and information-theoretically secure crypto techniques such as one time pads and secret sharing schemes.
Please consider any (original) code I post to Stack Overflow (and other Stack Exchange sites) to be released under CC-Zero unless stated otherwise. You may do whatever you want with it and don't have to credit me in any way, although of course that would be nice.
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May 10 |
comment |
Why is the basic (fixed-length) CBC MAC construction not a secure MAC when it is used on variable-sized messages? @imichaelmiers: To be fair, though, if fgrieu's hint isn't enough for the OP, they can always just look up the answer on Wikipedia. |
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May 10 |
comment |
2 ciphers to solve Ps. Your second ciphertext does not look like simple transposed English text to me, unless the plaintext is a Quick Query on the Quaint Quest for Quantum Queuing eQuations... |
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May 10 |
revised |
What does $(\mathbb{Z}_n^*)^2$ mean? edited tags |
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May 10 |
revised |
What kind of adversary is the cloud? fix repeated misspelling, other minor copyedits |
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May 9 |
comment |
Increased CRC collision probability when adding bits to input message @D.W.: Agreed, this question isn't really on topic here. Stack Overflow might be a better home for it. |
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May 9 |
comment |
Winzip AES256 vs PGP In addition to the file names, encrypted ZIP archives also leak the sizes and last modification timestamps of the unencrypted files and, if the older AE-1 format is used, their CRC checksums. Also, since they're vulnerable to various attacks if the attacker can modify the archive. These slides summarize some of the possible vulnerabilities. |
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May 7 |
revised |
secret-sharing wiki excerpt shorten excerpt; deleted 12 characters in body |
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May 7 |
revised |
How do you find a cheater in Shamir Secret Sharing? edited tags |
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May 7 |
revised |
Implementing secret reconstruction in Shamir's Secret Sharing better title, copyedit, add implementation tag |
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May 7 |
comment |
Indistinguishability attack example @juaninf: $m^{(0)}=m^{(1)}$ is useless, since that guarantees that nobody can distinguish the messages (since they're identical!). Now, $m^{(0)}_0=m^{(0)}_1$, on the other hand... |
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May 7 |
reviewed | Approve suggested edit on Indistinguishability attack example |
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May 5 |
answered | Implementing secret reconstruction in Shamir's Secret Sharing |
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May 4 |
comment |
Is there a secure cryptosystem that can be performed mentally? Ps. Here's a blog post I found with more details about the current security status of RC4. And yes, RC4-52 is probably less secure, and Solitaire even less so. They may both still be adequate for manual use (where messages are likely to be few and short), though. |
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May 4 |
comment |
Is there a secure cryptosystem that can be performed mentally? @SmitJohnth: If used properly (derive the message key using a secure hash, and/or discard at least the first 768 or so bytes of output, don't encrypt more than about 1GB per message key), RC4 is still considered secure, in the sense of "no known practical attacks." I still wouldn't recommend it for new designs. Hand ciphers are kind of a special case, though: on one hand, one generally doesn't expect as much security from a hand cipher as from a computerized one; on the other, it would be quite hard for anyone to generate as much encrypted material by hand as most of the known attacks need. |
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May 3 |
answered | Knowing a valid salted hash for an unknown secret, is it possible to compute another valid hash? |
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May 3 |
revised |
Knowing a valid salted hash for an unknown secret, is it possible to compute another valid hash? texify, paragraph formatting |
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May 2 |
awarded | Nice Answer |
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Apr 30 |
revised |
Adversary Two Stages quote formatting, add ind-cpa tag; needs further copyediting, but clarification from the OP would make that easier |
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Apr 30 |
answered | Adversary Two Stages |
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Apr 30 |
comment |
Adversary Two Stages Could you please provide a bit more context to your question? In particular, where did you see this paragraph, and what security property is it supposed to define? I can make some guesses based on what you wrote, but it would be nice to be able to tell for sure. |
