As the traditional story goes, the Surangama Sutra was smuggled from India and translated in China by a monk Paramiti. This is how the text's credibility is established: this is a book with an Indian provenance, and hence is credible. The 2009 translation includes the following on the title page:
Translated into Chinese during the Tang Dynasty by the Elder Monk Paramiti of Central India
Reviewed by the Elder Monk Meghasikha of Uddiyana
Verified by the Elder Monk Huaidi of Nanlou Monastery on Mt. Luofu
and so on
I'd like to know if there is any historical record of these figures (Paramiti, Meghasikha) and, if so, if they are associated with teachings like the Surangama. I'm interested in how bits of historical information can be used to increase faith in the teachings, as upaya; how much of the story behind the Surangama is grounded in some kind of history, and how much of it is something else?