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| bio | website | ethanheilman.tumblr.com |
|---|---|---|
| location | Cambridge, MA | |
| age | 30 | |
| visits | member for | 1 year, 10 months |
| seen | Apr 22 at 21:43 | |
| stats | profile views | 32 |
Security Hobbyist
Github: Ethan Heilman
Twitter: Ethan Heilman
Play FlipIt:
http://ethanheilman.github.com/flipIt/playable_with_instructions.html
Blog entries:
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Sep 23 |
answered | Is there a simple hash function that one can compute without a computer? |
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Sep 23 |
revised |
Is the following statement about PRG true or false? typo + reworded sentience |
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Sep 23 |
suggested | suggested edit on Is the following statement about PRG true or false? |
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Sep 23 |
comment |
Is the following statement about PRG true or false? What about using bar $|$ for concatenation? Is $.$ commonly used? |
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Sep 22 |
revised |
Designing a key expander out of ciphers Sentience was out of order, i corrected it. |
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Sep 22 |
comment |
Designing a key expander out of ciphers @DavidSchwartz - I've posted a complete version of my answer. |
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Sep 22 |
answered | Designing a key expander out of ciphers |
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Sep 21 |
comment |
Designing a key expander out of ciphers With a slight change you are correct. You can use all the ciphers in series with the key, $k$, xored in at each step so Eve could not construct a cipher that would reduce the entropy of the generated keys $k_{0}' ... k_{n}'$. |
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Sep 21 |
comment |
Designing a key expander out of ciphers @DavidSchwartz Alice and Bob share a set of ciphers and a key $k$. They wish to generate a set of keys, $k'_0 .. k'_n$, from the key, $k$, such that this set of keys will not allow Eve to learn the key, $k$, without her breaking all the ciphers. Alice and Bob have to both derive the generated keys $k'_0 ...$ from $k$ without communicating (no random values). |
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Sep 21 |
comment |
Designing a key expander out of ciphers This works for hiding the value of the key, but it doesn't work as a key expander since the keys generated are non-deterministic. If Bob uses your method, Alice won't be able to generate the same keys given the shared key. |
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Sep 20 |
revised |
Designing a key expander out of ciphers fixed |
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Sep 20 |
comment |
Designing a key expander out of ciphers @PaŭloEbermann Well played. Question edited to prevent cheating. |
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Sep 20 |
revised |
Changing algorithms during encryption added 150 characters in body |
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Sep 20 |
asked | Designing a key expander out of ciphers |
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Sep 20 |
answered | Changing algorithms during encryption |
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Sep 20 |
comment |
Why use an Initialization Vector (IV)? "Because the IV needs to change for every message." Pornin disagrees in his answer: "For instance, with MD5, the IV is fixed and this is not an issue." |
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Sep 20 |
revised |
What kind of attacks is this code vulnerable to? edited tags |
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Sep 20 |
awarded | Analytical |
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Sep 20 |
asked | Why use an Initialization Vector (IV)? |
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Sep 19 |
answered | What is the best method to determine the language used in a monoalphabetic substitution cipher? |
