# What is a trapdoor function used for?

## What is a trapdoor function used for?

In theoretical computer science and cryptography, a trapdoor function is a function that is easy to compute in one direction, yet difficult to compute in the opposite direction (finding its inverse) without special information, called the “trapdoor”.

What is trapdoor method?

A trapdoor one-way function is a one-way function with an additional requirement. Informally, a one-way function might be described as a function for which evaluation in one direction is straightforward, while computation in the reverse direction is far more difficult.

What is a lossy function?

For a lossy function, the encrypted matrix M is the all-zeros matrix M = 0. Then for every input x, the value f(x) is an entry-wise encryption of the all-zeros vector, so f intuitively “loses” x.

### What is a trapdoor function and why is it needed in Blockchain development?

What is a trapdoor function, and why is it needed in blockchain development? View answer. A trapdoor function is a function that is easy to compute in one direction but difficult to compute in the opposite direction unless you have special information.

Why trapdoor one-way function is the key concept for asymmetric key cryptography?

In each case an asymmetric algorithm is based on a type of function first suggested by Diffie and Hellman that has special properties known as trapdoor one-way functions. A trapdoor one-way function, if given some additional secret information, allows much easier computation of its inverse function.

Which of the following is based on trapdoor one-way function?

Public-key cryptosystems are based on (presumed) trap-door one-way functions. The public key gives information about the particular instance of the function; the private key gives information about the trap door.

#### What is a one-way trapdoor hash function give an example?

An example of a trapdoor one-way function is factorization of a product of two large primes. While selecting and verifying two large primes and multiplying them together is easy, factoring the resulting product is (as far as is known) very difficult.

Which of the following is another term for the trap door function?

As far as we know, both one-way and pseudorandom permutations do not help us to get public key encryption schemes. The way we obtain these is by using trapdoor functions (also known as trapdoor permutations).

What is a one way trapdoor hash function give an example?

## What is a trapdoor function?

A trapdoor function is a function that is easy to compute in one direction, yet believed to be difficult to compute in the opposite direction (finding its inverse) without special information, called the “trapdoor”. Trapdoor functions are widely used in cryptography .

What is a trapdoor permutation?

If each function in the collection above is a one-way permutation, then the collection is also called a trapdoor permutation. In the following two examples, we always assume it is difficult to factorize a large composite number (see Integer factorization ).

Is there a trapdoor function for discrete logarithms?

Functions related to the hardness of the discrete logarithm problem (either modulo a prime or in a group defined over an elliptic curve) are not known to be trapdoor functions, because there is no known “trapdoor” information about the group that enables the efficient computation of discrete logarithms.

### What is a backdoor in cryptography?

A backdoor is a deliberate mechanism that is added to a cryptographic algorithm (e.g., a key pair generation algorithm, digital signing algorithm, etc.) or operating system, for example, that permits one or more unauthorized parties to bypass or subvert the security of the system in some fashion. W. Diffie and M. Hellman.