Craig Wright says he is the author of a 2008 white paper, the foundational text of bitcoin and other cryptocurrencies, published in the name "Satoshi Nakamoto".
He argues this means he owns the copyright in the white paper and has intellectual property rights over the bitcoin blockchain.
But the Crypto Open Patent Alliance (COPA) - whose members include Twitter founder Dorsey's payments firm Block - is asking London's High Court to rule that Wright is not Satoshi.
The five-week hearing, at which Wright will give evidence from Tuesday, is the culmination of years of speculation about the true identity of Satoshi.
Wright first publicly claimed to be Satoshi in 2016 and has since taken legal action against cryptocurrency developers and exchanges.
COPA, however, says Wright has never provided any genuine proof, accusing him of repeatedly forging documents to support his claim, which Wright denies.
Wright sat in court as COPA's lawyer Jonathan Hough said his claim was "a brazen lie, an elaborate false narrative supported by forgery on an industrial scale".
Hough said that "there are elements of Dr Wright's conduct that stray into farce," citing his alleged use of ChatGPT to produce forgeries.
But he added: "Dr Wright's conduct is also deadly serious. On the basis of his dishonest claim to be Satoshi, he has pursued claims he puts at hundreds of billions of dollars, including against numerous private individuals."
Wright's lawyer Anthony Grabiner, however, argued in court filings that he has produced "clear evidence demonstrating his authorship of the white paper and creation of bitcoin".
Grabiner added that it was "striking" that no one else had publicly claimed to be Satoshi.
"If Dr Wright were not Satoshi, the real Satoshi would have been expected to come forward to counter the claim," he said.
