The difficulty would rise to compensate for the advent of quantum computing. The danger of quantum computing in bitcoin is holding the 51%+ computing power and

The difficulty would rise to compensate for the advent of quantum computing. The danger of quantum computing in bitcoin is holding the 51%+ computing power and being able to forge transactions in the 'books'. Source: http://bitcoin.stackexchange.com/questions/6062/what-effects-would-a-scalable-quantum-computer-have-on-bitcoin http://bitcoin.stackexchange.com/questions/6062/what-effects...