Not at all, rather it is the key that makes decentralization possible. The reason bitcoin can be decentralized is that ultimate authority comes, not from a cen

Not at all, rather it is the key that makes decentralization possible. The reason bitcoin can be decentralized is that ultimate authority comes, not from a central server, but from a consensus among the community of bitcoin processors and miners. The cryptography just enforces the consensus. In other words, ANYONE could write their own blockchain... even one that showed everyone else in the world giving all their money that person. It's just that no one would pay any attention to that blockchain... we'd all be working off the consensus view. This is also why bitcoin is resistant to being controlled by "the authorities", but not immune to it. If someone controlled over 50% of the compute power that's doing mining and processing payments, they could change the system and "fix" the numbers. The fact that it is decentralized is a defense against this because (hopefully) no one entity controls a significant portion of the compute power.