When we work in finite algebra and take into account the computational complexity of homomorphisms between objects (groups, rings, etc.) -- as it is required in cryptography and computational algebra -- we find ourselves in a strange world where, most likely, almost nothing is invertible. However, this non-invertibility, in its more important manifestations (which includes famous problems such as the Discrete Logarithm Problem over finite fields) had so far never been proven. But I will try to demonstrate that a sincere acceptance of this (thermodynamic in its nature) non-invertibility allows us to develop surprisingly efficient algorithms which solve previously inaccessible problems in computational group theory. This is a joint work with Sukru Yalcinkaya; I will describe and informally explain a few of our very recent results.