See this summary of PGP. The essential issue is that this allows one to construct mathematical functions which are difficult to calculate without secret information but anyone can easily verify that one has calculated the corresponding value given the “public key” (which Quirinius put on his userpage). Thus, to provide authentification that a message really came from the person who they claim to, they will provide both the message and f(message).
This rests on the RSA cryptographic system which relies on the fact that factoring integers is difficult.
If MWI is correct, and people trying to figure out my private key try to use quantum suicide to get my key then in the vast majority of the wave function I will observe my eavesdroppers having blown their brains out.
See this summary of PGP. The essential issue is that this allows one to construct mathematical functions which are difficult to calculate without secret information but anyone can easily verify that one has calculated the corresponding value given the “public key” (which Quirinius put on his userpage). Thus, to provide authentification that a message really came from the person who they claim to, they will provide both the message and f(message).
This rests on the RSA cryptographic system which relies on the fact that factoring integers is difficult.
Factoring integers isn’t hard.
If MWI is correct, and people trying to figure out my private key try to use quantum suicide to get my key then in the vast majority of the wave function I will observe my eavesdroppers having blown their brains out.