# All Questions

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### Private Set Intersection Polynomial Computation [duplicate]

I am trying to implement the protocol mentioned in Section 3.4 of “Efficient Robust Private Set Intersection” in Java. In the Second Step, the Client computes a polynomial of degree $n$ over the ...
2k views

### HMAC vs Encrypted Hash

What is best to use (for message integrity) between… AES(Data) + HMAC(Data) AES(Data + HMAC(Data)) AES(Data + Hash(Data)) …and why?
1k views

### RSA PCKS1 v2.1 RSAES-OAEP algorithm

Using RSA public key (n,e) the encryption of a message is c= (m^e) mod n and the corresponding message is decrypted as ...
191 views

### Is there a way to encrypt multiple sets of data into one result, with separate keys decrypting each set of data

What I am picturing is something like this: Block A: "Hello, how are you today?" Block B: "The weather reminds me of summer." I encode this, giving me two keys and a resulting encrypted block e.g. ...
534 views

### Is this scheme a provably fair random number generation?

I have thought up a method for generating random numbers between a client and a server which I hope is fair: The client and server decide on a range in advance, $0$ trough $n-1$. The server ...
837 views

### Is the AES encryption scheme CPA secure?

Give a 256 bit key space and 128 message space would AES block cipher as the encryption scheme be CPA secure?
49 views

### How to generate a bilinear group of prime order p for key generation

I asked the same question before. But an unregistered user i haven't any privilege to comment. So i am repeating my same question. I am trying to implement an IEEE Paper In Cryptography. I read many ...
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### Elliptical curve cryptography Determine if a public key point y is negative or positive, odd or even?

Take a Elliptical curve cryptography public key (x, y) and its additive inverse (x, -y). How do you identify which is the positive point and which is the negative point? Example Private key 1 -> (x, ...
58 views

### TLS1.2 Client Finished Message

Can someone make sure I'm creating my Client finished message properly as I've been working at this for days and keep getting a Bad record MAC error and I have no idea what I'm doing wrong. First ...
168 views

### Reversing a Psuedo Crytographic Hash [closed]

I'm trying to get a better understanding of cryptographic hashing. Take the example transformation function below, is it possible to reverse this formula to solve/isolate for message[i]? ...
165 views

### what is SALSA20 Nonce and its requirements [duplicate]

what is the source of nonce in SALSA20 algorithm. basically who provides the value of nonce in SALSA20 algorithm
1k views

### Vigenere ciphertext encrypted with another vigenere cipher

I have been learning about Vigenere ciphers and then thought of this scenario: if a cryptographer encrypts a plaintext English message with a Vigenere cipher and then another cryptographer, who wants ...
541 views

### With HMAC, can an attacker recover the key, given many known plaintext/tag pairs?

Given many pairs of $(m, t)$, can the attacker compute the key $k$ satisfying $\text{HMAC}(k,m) = t$? (Assume that $k$ was chosen at random.)
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### What length should the padding be when encrypting or signing with RSA?

I am wondering what length the padding should be when encrypting or signing with RSA. Does it matter what length the padding is, and if so — what length should it be? Another point: Should it be ...
309 views

### Cryptography based upon neural networks [closed]

I would like learn about use neural networks in cryptography. Is there any research literature on this subject? What should I do to learn about the subject? I am taking short course in neural ...
81 views

### Would this be a plausible authenticated encryption scheme using nested encryption?

[This is was the most promising out of an incrementally developed set of (mostly flawed, to some degree) schemes I posted here, but I was told I should post each one separately] This scheme is highly ...
1k views

### Is it possible to generate an RSA SHA1 signature only from a public key?

Is it possible to generate signature only from Public key. See example below where i have valid signature but what if I change hash ? Is then any way to do this? Public key(160 bytes): ...