Prediction:

The megatrend in cryptography of the 2010s was elliptic curves, pairings and general purpose ZKPs/SNARKs.

The megatrend of the 2020s will be (in addition to broad adoption of the above) lattices, LWE, multilinear maps, homomorphic encryption, MPC and obfuscation.

The common theme in both is the rise of cryptographic primitives that operate over boolean or arithmetic circuits as a mathematical representation of computation, and hence cryptographic constructions becoming general purpose.