NEW YORK (AP) — Australian entrepreneur Craig Wright, the man who came forward this week as bitcoin's founder, is backtracking. He wrote in a blog post that he does not "have the courage" to publish additional proof, as promised, that he is the elusive creator of the Internet currency.

Wright said on Wednesday that he would provide additional proof to back up his assertion, which drew widespread skepticism. Instead, he scrubbed his blog clean of past entries and posted a short statement titled "I'm Sorry."

Wright didn't explicitly withdraw his claim to be Satoshi Nakamoto, bitcoin's mysterious founder; he wrote that he thought he could "put the years of anonymity and hiding behind me." But as this week's events unfolded, he wrote that he is "not strong enough for this."