PALO ALTO, Calif. — When a cryptocurrency start-up that promised to revolutionize the fruit and vegetable industry shut down last month, it left behind one word on its website: penis.

When a virtual currency company called DateCoin recently tried to entice investors for its initial coin offering, it posted a Facebook ad that featured a reclining woman in a swimsuit with text over her body that read, “Touch my I.C.O.”

And after the North American Bitcoin Conference in January, which highlighted 84 male speakers and three women, the official conference party was held at a Miami strip club.

Virtual currencies and blockchain, the digital ledger that forms the basis of the cryptocurrencies, were intended to be democratizing and equalizing forces, buoyed by a utopian exuberance. But women who have been trying to participate in the gold rush are finding a lopsided gender divide. And some say the culture is getting worse, with the male-dominated culture buoyed by a new fleet of wealthy crypto speculators known as “blockchain bros.”