Without knowledge of s the function f is a one way function given s inverting f is easy.
Trapdoor one way function rsa.
For fixed public key is viewed as a function of that maps bits to bits.
F d r is a trap door one way function if there is a trap door s such that.
Is rsa a one way permutation.
And formally the way we state that is that basically for all efficient algorithms a it so happens that if i generate two primes p and q random primes p and q.
And so to argue that this function is one way we basically state the rsa assumption which basically says that the rsa function is a one way permutation.
Hard step 2.
A trapdoor one way function is a function that is easy to compute but computationally hard to reverse easy to calculate f x from hard to invert.
Page 17 how hard is computing e th roots modulo n.
Is a trapdoor one way hash function if is also a one way hash function i e if additionally.
Rsa as a one way trapdoor function.
In mathematical terms if f is a trapdoor function then there exists some secret information t such that given f x and t it is easy to.
To calculate xfrom f a trapdoor one way function has one more property that with certain knowledge it is easy to invert to calculate x from f x there is no proof that trapdoor one way functions.
Then there is an efficient algorithm that on input produces such that for some trapdoor key.
M from c m e mod n.
Find e th roots modulo p and q.
To invert the rsa one way function without d attacker must compute.
X xe mod n hard easy easy with trapdoor info d trap door owf definition.
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.
It is a one way function and.