Why are 256bits "enough"?

[riddim]

The second last message of Timo is interesting - there he did what we were looking for

@Tim87

To spice it up even more, let’s assume a trillion times more blocks, and “only” SHA-256: the chances that the hashes of any of our 160 trillion trillion messages collide is around 0.00000000000000000000000011. I think we’re safe on this front.