# All Questions

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25 views

### Group Signatures with VLR Revocation Check

I was reading the paper by Boneh et al. Link. The scheme describes what is called a Verifier Local Revocation Technique. The Scheme assumes that a Revocation List [RL] allows each verifier to check ...
64 views

### Is there a cryptosystem which allows slicing and concatenating strings without decryption?

I want a cryptosystem with the following four functions: ...
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### tshark decryption fails on old OS but succeeds on new OS [migrated]

I have a pcap tracefile and private RSA key that should allow me to decrypt the HTTPS data in the pcap file. With the exact same pcap file, private key and tshark command, I find that decryption ...
39 views

### One-way Functions for Floating Points

Are there any commutative one-way functions for floating points? I tried to explain why I need these functions. First, I describe the problem on a high level and then I further formalize it; There ...
48 views

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### How to use SHA-512 in terminal? [migrated]

I do not understand this problem. I tried my code down below. It says,"can only sign or verify one file." Instructions: Using the hash function SHA‐512 and the key ...
75 views

### SHA3-512 troubleshooting - is there a worked example for hashing the “zero-length string”?

(I wondered if this question should be asked on StackOverflow instead because it's a programming related issue, but it's bound to the intricacies of SHA3, which I figured was a better fit for Crypto....
75 views

### Can Trivium be used as a PRF?

The Trivium encryption algorithm has two inputs, key and IV, both of which are 80 bits long. Let's call it Trivium(key, IV) → keystream. My question is whether doing Trivium(key, input) and taking the ...
28 views

### ASCII characters in an image steganography [duplicate]

Given an image size of 300 by 400, what is the maximum number of ASCII characters (7 bits) that can be embedded using the LSB steganography? I would assume that every pixel can perform an LSB so ...
43 views

### Is the 51% attack the only technical reason no country will ever adopt Bitcoin as a state currency? [closed]

Is the 51% attack the only technical reason no country will adopt Bitcoin as a state currency? Let's suppose a country with a GDP size less than 300 Billion USD adopt the Bitcoin as an official ...
17 views

### How to create a generator for a $Q_3$ access structure?

I'm reading about access structures used for multiparty-computation from https://eprint.iacr.org/2004/245 and https://eprint.iacr.org/2000/037. My understand is that to actually use the access ...
157 views

### CRC32 catches errors, but then what's the point of SHA?

If crc or CRC32 is specially designed to catch errors, then what's the point of SHA or md4-5 or any other hashing function? What I did was, I had a 190 mb png file (rendered in 16k resolution with ...
57 views

### In RSA, how do you find d with a very large e?

If I had N and E, how would I be able to find D? The catch here is E is extremely large -> like 310 digits. I think this set of numbers is vunerable because E should be relatively small. How can I ...
33 views

### Byzantine Agreement: Why does OM need f+1 rounds in a synchronous setting?

To get Byzantine Fault Tolerance in a synchronous model you can use an Oral Message Algorithm. For n > 3f+1 it gets an Byzantine agreement in ...
90 views

### Derivation of birthday paradox probability

I am trying to come up with an explanation of the probability of birthday collision. $P$(no collision among t people) = $(1− \frac{1}{365}) · (1-\frac{2}{365}) ··· (1-\frac{t-1}{365})$ For one ...
Paillier Cryptosystem depends on both the factorization where $n = p.q$ and the complex residuosity problem which is defined in the original paper as: The problem of deciding n-th residuosity, i.e. ...