As for Sandaihiho-sho, a research group including Zuiei ITO, a monk of Nichiren Sect, are almost certain that it is Shinseki (original handwriting) after having computer analysis.
三大秘法抄については日蓮宗僧侶の伊藤瑞叡らの研究グループによってコンピュータ解析がなされて、真跡だと確定しつつある。