SHA-1 encryption has been broken by a team of researchers; Xiaoyun Wang, Yiqun Lisa Yin, and Hongbo Yu, and apparently they have been shadily distributing their paper, but its not readily publicly available. They used hash collisions to break the encryption. I personally know calculus, differential equations, greens and stokes theorem, and linear albegra, but this type of math is still way over my head. From my limited understanding on this...hash collisions would be the only real way to actually crack the encryption (vs. bypass, or the work you have been doing..), and considering that it has already been done, then I suppose that makes it a viable solution. I don't know if a team of researchers from Shandong University in China would care enough about the android hacker community to share their findings... but I suppose anything is possible. If in fact they were willing to share this information, the function could be used in a powerful computational program such as Maple, Matlab, or Mathmatica, to generate the private keys... but I think you might need the public key..? Like I said...I really only have a surface-level understanding of whats involved.