# How do you calculate D in SA?

## How do you calculate D in SA?

To compute the value for d, use the Extended Euclidean Algorithm to calculate d=e−1modϕ, also written d=(1/e)modϕ.

### How is public key calculated?

Private Key d is calculated from p, q, and e. For given n and e, there is unique number d. Number d is the inverse of e modulo (p – 1)(q – 1). This means that d is the number less than (p – 1)(q – 1) such that when multiplied by e, it is equal to 1 modulo (p – 1)(q – 1).

**How do I find my public key and private key?**

No, there is no known efficient method to find an RSA private key from public key, ciphertext and plaintext, including when no padding is used and e=3. The best known method is factoring the public modulus, which then trivially allows to find a working private key.

**How do you find D in statistics?**

- The standard deviation formula may look confusing, but it will make sense after we break it down.
- Step 1: Find the mean.
- Step 2: For each data point, find the square of its distance to the mean.
- Step 3: Sum the values from Step 2.
- Step 4: Divide by the number of data points.
- Step 5: Take the square root.

## How do you calculate modulus?

How to calculate the modulo – an example

- Start by choosing the initial number (before performing the modulo operation).
- Choose the divisor.
- Divide one number by the other, rounding down: 250 / 24 = 10 .
- Multiply the divisor by the quotient.
- Subtract this number from your initial number (dividend).

### How do you send a public key?

Use one of the following social platforms.

- Twitter: Simply copy your OpenPGP public key text and send it as a direct message to your recipient.
- Facebook: Simply copy your OpenPGP public key text and send it as a direct message to your recipient.

**Can I generate private key from public key?**

You cannot generate private key from public key but you can generate public key from the private key using puttygen. As @alfasin mentioned if you could generate the private key from public key then RSA would be useless and this would make you vulnerable to attack.

**What is the math behind the private key?**

You can trivially take n = 91 and guess p and q with simple factorization: Redo all the math above and you have the private key. Doh~ This takes a really long time. Even fancy solutions on the fastest computer on Earth would take until the end of the universe.

## How are the private and public keys calculated?

It is based on the difficulty of factoring the product of two large prime numbers. If we already have calculated the private ”d” and the public key ”e” and a public modulus ”n”, we can jump forward to encrypting and decrypting messages (if you haven’t calculated them, please scroll downfurther this blog post).

### Which is the simplest explanation of the math behind public key?

There’s a lot more to it than this (like padding) but this is the gist of it. 1. Pick two prime numbers: 2. Multiply them together: 3. Compute Euler’s ” totient ” function of n: 4. Pick a random number e such that: and e is ” coprime ” with φ (n), meaning it has no common factors.

**What are the numbers for Jacks public key?**

How the conversion is done, is up to other algorithm) Jacks public key consist of number e = 17 and n = 3233. Now Alice has the message encrypted with Jacks public key. Alice send the ”c”, ciphertext to Jack.