The judge in the Sterlingov case pointed out in his ruling on the admissibility of blockchain forensic evidence that the DOJ had additional evidence pointing to the defendant. “This is not a case in which the government’s theory that Sterlingov was the operator of Bitcoin Fog turns exclusively, or even primarily, on [on blockchain forensics]“, he wrote. In order to “establish this crucial point,” the judge noted, the government relied on a range of information external to any blockchain, from IP addresses to forum posts.

The judge also took issue with the description of Chainalysis software as an impenetrable black box, on the grounds that the defense had received information about its operation – Ekeland disputes this characterization – and pointed out that the underlying heuristics applied by the company have been submitted for peer review, although its specific grouping methods have not.

For maximum transparency, Chainalysis could open source its software, but this would risk giving bad actors an advantage. “It’s a game of cat and mouse,” says Mieklejohn. “Once you publish the heuristics, people understand how they work, and they can then take steps to escape those heuristics.” Under these circumstances, says Chainalysis CEO Gronager, admissibility hearings, in which the company’s work was subjected to intense scrutiny, are the next best thing to a traditional peer review.

Ultimately, efforts to cast doubt on the reliability of blockchain forensics bore no fruit for the defense. “The Court is convinced that the analysis of blockchain in general, and [Chainalysis’ software] in particular, it is not junk science,” the judge wrote in his summary on the admissibility question.

The ruling does not set a precedent that other U.S. judges should follow, as the case has so far been confined to district court. Nonetheless, Gronager hopes that this will be the “final word” on the admissibility of blockchain forensic evidence, at least until future developments in cryptographic tracing require reevaluation. “This is a historic decision,” adds Bisbee of Chainalysis.

While Ekeland worries about a “mushroom effect,” whereby the decision would figure into the thinking of future judges, he says the case “could take years to solidify one way or the other.” . Among other squabbles over how the case was decided, the use of blockchain forensic evidence will form part of the basis of Sterlingov’s appeal. “Right now, the momentum is in their favor,” Ekeland says. “But it’s still an open battlefield.”