wonce
  • Member for 7 years, 10 months
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3 answers
10 votes
3k views
How to prove identity without revealing identity
8 votes

She can generate a key-pair and include the public key in the book. Having the private counterpart she can at any time proove that she wrote the book by signing an arbitrary statament.

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1 answers
0 votes
165 views
How can I process data within a cloud securely?
Accepted answer
4 votes

In general this seems not possible. To process the data, you need to have it in plaintext, and if you have it in plaintext an admin might read it. However, if your processing needs to read only some ...

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1 answers
1 votes
152 views
Is knowing the distribution of input domain only way to do cipher text only attacks?
4 votes

Since for any fixed key the encryption algorithm is a bijection from the set of $n$-bit strings onto itself, the set of all possible ciphertexts is regardless of the key and algorithm always the set ...

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1 answers
2 votes
4k views
Monoalphabetic cipher key
Accepted answer
3 votes

The key to a mono-alphabetic substitution cipher is a substitution table. Thus you already have (most of) the key for that cipher, it is a b c d e f g h i j ? D E F G H ...

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1 answers
4 votes
176 views
Clarification of the terms "brute force" and "guess"
Accepted answer
2 votes

The difference in that answer is that brute force refers to an exhaustive guessing attack (having guaranteed success but requiring exponential time) whereas guessing (a polynomial number of) random ...

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3 answers
4 votes
6k views
Encryption of log files
2 votes

Considering that you can never really solve your problem as long as you are running in an untrusted environment, your solution is fine. To append to an old logfile you need to read the last and ...

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1 answers
0 votes
346 views
Executing encrypted code?
1 votes

No, assuming your code is running in an environment completely controlled by an adversary (no TPM etc.). Note that if the instructions were encrypted in some way we assume an adversary could simply ...

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1 answers
0 votes
175 views
Client-server communication
Accepted answer
1 votes

If your environment was fully compromised you could at no point actually decrypt your data, defeating the purpose. So I’m going to assume the user only uses an authentic client and the client’s memory ...

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2 answers
1 votes
2k views
Does google's Crypto.JS AES encryption use PBKDF2 as default?
1 votes

I assume you are invoking it like this: CryptoJS.AES.encrypt("Message", "Secret Passphrase"); As of 3.1.2 the default key derivation function is OpenSSLKdf as configured here and implemented here ...

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1 answers
0 votes
30 views
Hash system to generate same (specified) hash from multiple datasets?
Accepted answer
0 votes

No (assuming by “better” you mean “cryptographically strong”). What you are trying to do is finding a pre-image of $X$ under the extra condition that $D_i$ must be a prefix of the pre-image. ...

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2 answers
2 votes
1k views
Large file validation on an embedded system through hash and encryption
0 votes

Your idea does not seem to provide any security benefit. If an attacker was able to modify the data while preserving the MD5 hash, your encrypted MD5 hash would also stay the same. One practicable ...

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