Say, you have a friend who is truly a very promising artist, and you want to help her to protect her work.
One way is to advise her to use her mobile phone to capture each of her art work and send them to you, you then, you either hash or apply other encryption algorithm to each art work image and store them in a safe place.
Then, at a future date, some con artist or the like tries to steal her intellectual property / art work by faking her work, she could take an image at such fake work and compare the hash value of each art work to detect fakes.
a) would same authentic image of different size generate different hash value even with the same/exact hash method?
b) would same authentic image of the same size captured by different maker of mobile phone generate different hash value even using the same hash method?
And any further thoughts on the subject would be much appreciated.