We have just observed a significant step up in the difficulty of Bitcoin hashes. This has come after a sharp rise in the total number of hashes per second on the Bitcoin network. Over the past 24 hours the hash rate has jumped from 127701 GH/s to 148527GH/s, according to Blockchain.info. This is one of the fastest and biggest changes in the history of the bitcoin protocol and demonstrates a continuing exponential growth in not just the difficulty of the proof-of-work calculations, but in the computing power being brought to bear on generating the currency.
According to blockexplorer.com, the current difficulty of computing bitcoin blocks is rated at 15605632.681286. Around this time last year, the figure was approximately 13478. Which shows a 1158% YoY growth, and a 495% QoQ growth in difficulty.
Similarly for the hash rate, which is now at 148527 GH/s (giga-hashes per second), this shows an increase of 1111% YoY and 478% QoQ.