For the RSA verification that you asked to bypass, I don't know whether it would work in your device, but it worked in my little experiment. In Lollipop, the ADB keys (after authorization) are saved in
/data/misc/adb/adb_keys. Your private key is saved in computer. In Linux the directory location is
$HOME/.android/. On Windows that usually translates to
%USERPROFILE%\.android, but keys might end up in
C:\Windows\System32\config\systemprofile\.android in some cases. (Source)
There is a method described here by ashoke which might help out in bypassing the authorization.
However, in my Lollipop, the method varies. I noticed that in my primary and secondary Lollipop ROM the
adb_keys had the same key actually. All I did was revoke the authorization from the secondary ROM (file deleted automatically ), disconnected device from PC, copied
adb_keys from Primary ROM into secondary ROM, connected the device into PC, and voila! I wasn't asked for that authorization. I double checked the authorization using
adb devices and it was all good.
Try the linked answer first. Authorize a different Android phone, copy its keys into your device from Recovery mode and see if it works.