If i'm understanding you correctly you want to train a second system with a first system's authorized user, then use the 'key' to open the first system. A some

If i'm understanding you correctly you want to train a second system with a first system's authorized user, then use the 'key' to open the first system. A someone who actively researches biometrics I can't say that this is a good method for a few reasons. 1) Systems often train templates which look very different than the original input, especially if more than one image is involved in training. These templates aren't necessarily going to be recognizable to the first system (even if they can be represented as a 2D image). 2) Many enterprise systems (such as from Honeywell or whoever) include liveness tests and spoofing measures. Though anecdotally they are not very good, they check for basic measures such as if the pupil expands and contracts from a burst of light. 3) Most biometrics that involve access to some place (verification) usually include a 3rd party monitoring said access. If you were to do this for say someone's home. Depending on the system you may gain access with a high definition photo as many consumer systems are set to a higher false accept rate (FAR) to prevent user aggravation. However, if they set it to be very strict (giving a larger false reject rate) then the best way would probably be attack at their sensor directly. That is, the system often doesn't care about the surroundings, it's trained for one task (open if authorized user).