At the time of Christ the Jews had a Sanhedrin, and the head of them and the priests was the high priest who presided over the administration of the temple. Since the temple's destruction there has been no high priest, but a few years ago the Jews formed a Sanhedin consisting of 71 rabbis.
It's this Sanhedrin that will be responsible for authenticating a Messiah should a false Messiah come on the scene. One criteria a Messiah has to pass is he must be able to reliably trace his linage back to king David.
I just read a comment from a Jew at another site about how they could select the temple priests for a rebuilt temple. He wrote the following:
"We stopped having priests (high or otherwise) when the Temple was destroyed, around 70 CE. Those of the priestly tribe (by and large) know their lineage, but the functions they would perform cannot be done outside the Temple. Until such time as it is rebuilt, they will not be able to perform those duties. Interestingly, those lineages can now be proven with DNA; the Cohen Modal Haplotype occurs in about 50 percent of self-identified kohanim, as opposed to only about 10 percent of the males in the general Jewish population."
When I read that it made me think about how they could authenticate a Messiah from the linage of David. I've read that some Jews in Israel, even one of those on the newly formed Sanhedrin, can trace their linage back to king David. All they would need to do would be to compare DNA from a supposed Messiah with the DNA from those whom are believed to be descendants of king David to authenticate his ancestrial linage.
Another criteria to confirm a Messiah is he must perform some verifiable miracle.
Reading about the second beast in Rev. 13:13-14, and the son of perdition in 2 Thess. 2:9-10 it says he will deceive people by performing miracles. But of course the miracles are from the devil.
Here's an article by Hal Lindsey about the forming of the Sanhedrin that he says is necessary for rebuilding a temple and chosing a Messiah.