# Tag Info

Accepted

### Do these new insights into prime numbers affect encryption security?

No, because these new insights only affect the discovery and patterns regarding finding new prime numbers. In order to break existing encryption algorithms that rely on primes such as RSA, you'd have ...

### Do these new insights into prime numbers affect encryption security?

No, because that "discovery" produces nothing of value. They examined prime numbers up to one billion. In that range, about one in eight numbers ending in 1, 3, 7 or 9 are prime numbers, and which ...
• 1,052
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### Can we pick which key is private or public in asymmetric encryption? Do the keys actually encrypt and decrypt a cipher text?

No no no! You don't get to pick which key is private and which public. That false sense of freedom is due to people not understanding that public-key cryptography is conceptually different from ...
• 6,541

### Why is the private key generated first in public key crypto?

In general, the public and private keys are computed together. For some schemes, the public key is computed from the private key. ElGamal is an example. (The system parameters include a suitable ...
• 4,382
Accepted

### Are all possible EC private keys valid?

I'll consider that you are using a 256-bit curve per ANS X9.62:2005. Not all 256-bit bitstrings are a formally valid private key; when using big-endian conventions, these must represent a strictly ...
• 122k

### Can we pick which key is private or public in asymmetric encryption? Do the keys actually encrypt and decrypt a cipher text?

After generating a key-pair can we pick which key will be private or public? No, in general we cannot. For most asymmetric cryptosystems the private and public keys are completely different kinds of ...
• 44.2k

### Are all possible EC private keys valid?

There are three ways to look at it: The mathematics. An elliptic curve key pair is defined as $s, s \cdot G$, where $s$ is an integer, $G$ is the base point and $\cdot$ is elliptic curve point ...
• 31.2k
Accepted

### State of the art RSA key generation

There is consensus that it is safe to use random primes $p$ and $q$ when generating 2048-bit (or wider) RSA public moduli which two prime factors $p$ and $q$ are about half the key size. That is ...
• 122k
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### Generating a NIST P-256 private key

A NIST P-256 secret key (for ECDH or ECDSA) represents any scalar modulo $\ell$ for $$\ell = 2^{256} - 432420386565659656852420866394968145599,$$ whereas an X25519 secret key represents an integer ...
• 45.6k
Accepted

• 131k

### Where do key generation algorithms take the randomness from?

Applications that generate key get the randomness (entropy) from the operating system. The operating system, in turn, gets the randomness where it can find it. Ideally the OS gets randomness from a ...
Accepted

### How to Check Strength of RSA Public Private Key

RSA public/private key pairs are no exception: there is no way to assess that a cryptographic key is strong by looking at its value; only ways to assess that it is weak. And lack of signs that it is ...
• 122k

### Can we pick which key is private or public in asymmetric encryption? Do the keys actually encrypt and decrypt a cipher text?

The existing answers from DannyNiu and Meir Maor answer well the confusion about whether private and public keys are interchangeable. But it is also worthwhile, I think, to address this snippet from ...
Accepted

### Can I use an ECDH Shared Secret from the same Private / Public Key Pair?

No, it's not a problem. What you've found is known as the square computational diffie-hellman problem(SCDH) and it can be shown that this is equivalent to the computational diffie-hellman problem(CDH)...
• 44.5k