Page "Public-key cryptography" Paragraph 22

Some encryption schemes can be proven secure on the basis of the presumed difficulty of a mathematical problem, such as factoring the product of two large primes or computing discrete logarithms.

Note that " secure " here has a precise mathematical meaning, and there are multiple different ( meaningful ) definitions of what it means for an encryption scheme to be " secure ".

The " right " definition depends on the context in which the scheme will be deployed.