Why is "quantum-safe" or "post-quantum" cryptography becoming a focal point in modern cryptographic discussions?

What's the cryptographic difference between MIME and S/MIME?

The creation of public key cryptography was driven by the need to address two fundamental issues, the first of which is key delivery. Use an example to briefly demonstrate how key distribution may be performed.

With better cryptanalysis tools at hand, more and more people are turning to quantum computers. At least three, but no more than five, of the most recent works on quantum computing and password cracking should be read and understood. In a short paper of only a page or two, you may discuss the benefits and drawbacks of quantum computing.