As far as I am aware, they are not completely useless computations. Isn't the model supposed to be that transactions are verified using calculations of effecti

As far as I am aware, they are not completely useless computations. Isn't the model supposed to be that transactions are verified using calculations of effectively a tuned brute force method where the brute force needed is tuned to the power of the network. Tuning the difficulty means that no-one else can beat it to the brute force goal without having comparable computational power. In that sense the computation no less useless than any other cryptographic technique that has complexity to thwart brute force attacks. [I may be completely off base here, I wouldn't call myself a bitcoin expert, but this is how I perceived it]