# All Questions

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### Multivariate Cryptography: What is the secret oil space in the MAYO signature scheme?

IN UOV schemes, I understand that you need to choose a secret subspace $O \in \mathcal{F}^q_n$ such that $P(\mathbf{o}) = 0$ for all $\mathbf{o} \in O$. According to the paper Improved cryptanalysis ...
2k views

### Difficulty of Reversing Elliptic Curve

In ECC, it is apparently easy to verify the final point given the starting point and the number of hops. But it is difficult to compute the number of hops given just the starting point and the final ...
1 vote
46 views

### Is there any notion of key-recovery attacks security (perhaphs using games) that is equivalent to IND-CPA?

I am talking about Symmetric Cryptography only in the following. We know that Semantic Security (in the presence of eavesdropper) implies security against message recovery (in the presence of ...
1 vote
939 views

### What is the order of the generator point G=9 in curve25519?

In Curve25519 we typically have this generator point or base point: ...
107 views

### can we modify the prime field by increasing it in secp256k1?

If in ECDSA secp256k1 we have the prime field p=2256 - 232 - 29 - 28 - 27 - 26 - 24 - 1, can we increase it to p=2256, if we keep the double and add operations the same, the curve equation the same ...
1 vote
184 views

### Exponentiation Problem of G2 in MNT curve

I made a simple python program in the Charm framework (https://github.com/JHUISI/charm): ...
265 views

### Good Diffie-Hellman Encryption Method

I've just made my own implementation of Diffie-Hellman in nodejs (it's for a project of mine). However, the shared keys are integers; I want to use those integers as a key to encrypt data. This is an ...
12k views

### Kerckhoffs’ principles – Why should I make my cipher public?

As I understand it, the less people know about the internals of my protocol or cipher, the more secure the protocol is. However Kerckhoffs's principle states that A cryptosystem should be secure ...
2k views

### Find ECDSA PrivKey to PubKey = 0

I know it should be impossible (or at least infeasibly hard) to extract a ECDSA Private Key from a given Public Key (discrete logarithm problem). But I'm not deep enough into ECC to find an answer to ...
1k views

### How to find at least one private key from a large list of compressed public keys secp256k1

Not long ago I saw a discussion on the Bitcoin Talk forum: https://bitcointalk.org/index.php?topic=5060735.msg50736695#msg50736695 Please give advice and working methods? Is it possible to find at ...
3k views

### Why is it impossible to find the private key from the public key?

From what I understand, based on the article A Beginner’s Guide: Private and Public Key Cryptography Deciphered, the public key is generated by performing $n$ tangent plus mirroring operations from ...
1 vote
125 views

### How to generate 24 bytes CMAC using AES-192 or AES-256

Is it possible to generate a 24 bytes CMAC using AES-192 or AES-256 and if so, how? According to AN10922AN10922.0df,looks like we can generate 24 bytes and 32 bytes key using div constant ?
43 views

### Why not flip random bits of the encrypted message for additional security? (hybrid system)

Suppose a binary word of $n$ bits is the result of encryption (doesn't matter with what algorithm) that now has to be sent from person A to person B. Suppose additionally, A and B have a symmetric key ...
49 views