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| bio | website | |
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| location | ||
| age | ||
| visits | member for | 1 year, 9 months |
| seen | 1 hour ago | |
| stats | profile views | 137 |
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3h |
answered | Requiring a “supervisor” key pair and a “user” key pair to decrypt multiple-recipient messages |
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3h |
comment |
Requiring a “supervisor” key pair and a “user” key pair to decrypt multiple-recipient messages I think there's something wrong with your proposal. How does step 1 work, if Bob knows the message and Jim doesn't? What does it mean to encrypt with a private key? (Are you talking about signing? Signatures are not the same thing as encrypting with a private key.) When you say "his", who does that pronoun refer to: Jim, Bob, or Mark? |
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3h |
answered | How does the birthday attack work in AUTH and UF-CMA games? |
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1d |
comment |
Hill-cipher, disordered alphabet user9, Please do not deface your question! This site is intended to be a question-and-answer site for the common good. In particular, when you post here, you accept that the community has some ownership of your question; you are not a sole owner. If you deface your question, you render it useless to others -- which is inappropriate, as the main purpose of this site is to be useful to the world, not just to you. It is considered inappropriate to deface or delete your own question after you received an answer. See, e.g., meta.stackoverflow.com/q/106807/160917 |
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1d |
awarded | Cleanup |
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1d |
revised |
Hill-cipher, disordered alphabet rolled back to a previous revision |
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1d |
comment |
How random are comercial TRNGS I think the question, as stated, is a perfectly fine question. It's not asking for product recommendations; it is asking about how one can evaluate a range of products out there. Seems like a great question to me! (The follow-on questions in the comments about specific products, however, are not good questions: they do not belong on this site. Search for "shopping question" to learn more about why not.) |
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1d |
answered | Perfect Secrecy, two Definitions |
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1d |
comment |
How much data can I encrypt with AES before I need to change the key in CBC mode? @makerofthings7, to understand what it means, start by understanding what 'advantage' means at a deep level. At a very rough, crude level, you can think of it as representing the probability that an attacker learns some information about the message. (However, strictly speaking, this is a simplification.) In this case, we are saying roughly "If you encrypt no more than $2^{48}$ blocks of data under the same key, the probability that the attacker learns some information about the message is at most $1/2^{32}$". Roughly. |
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1d |
answered | Do I need to keep a 64-bit version number secret? |
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1d |
answered | How much data can I encrypt with AES before I need to change the key in CBC mode? |
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May 20 |
comment |
Is this a sensible cryptographic protocol intending to reduce the impact of compromised security? @MattFellows, well, here's one scenario that comes to mind: what if they breach one of those systems first, then use it as a jumping-off point to attack your server? P.S. If the server is only intended to be accessed by limited IP addresses, it might be worthwhile to set up a firewall (or TCP wrappers policy) to actively block connection attempts from any other IP address. |
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May 20 |
comment |
Are there any hand ciphers not obsoleted by computer cryptanalysis? Thanks, @PaŭloEbermann. Yes, I'm aware of it. (For reasons that probably aren't relevant to anyone else, it doesn't work for me: on my primary platform, something on my browser's configuration makes the "close" link not work. Maybe an ad blocker or something, I've never taken the time to fully trouble shoot it. My apologies for cluttering things up with comments as a result.) |
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May 19 |
comment |
Recommended way of adding a pepper/secret key to password before hashing? @TheDisintegrator, the pepper should be truly random (e.g., generated from /dev/urandom and kept secret thereafter). I don't know about what order your $hash_h mac$ accepts parameters in; I explain where the inputs should go in my answer. As far as how to call bcrypt, that will depend upon your particular language and library's API. If you want to know how to code this up, that's better for StackOverflow. You choose the work factor for bcrypt so that computing bcrypt takes, say, 50ms. |
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May 19 |
comment |
Are there any hand ciphers not obsoleted by computer cryptanalysis? Duplicate of crypto.stackexchange.com/q/1653/351 (see also crypto.stackexchange.com/q/844/351). |
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May 19 |
answered | Why this k parameter is in unary in adversary PPT algorithm? |
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May 18 |
comment |
When truncating an AES MAC value by “w” , how do I justify that “w” is still negligible? @Maeher, I have a different take. I think it's a perfectly reasonable use of the term. Outside of complexity theory, the standard engineering meaning of the term "negligible" is "so small it can be safely ignored/safely treated as zero". That seems to apply fine here. |
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May 18 |
comment |
Alternatives to HMAC + CBC? It doesn't matter whether you separate out the signature into a separate column or not. |
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May 18 |
revised |
Alternatives to HMAC + CBC? added 485 characters in body |
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May 18 |
answered | Alternatives to HMAC + CBC? |
