I was betatesting a program that is not only doing checksum, but also lossless compression of DNG files on the fly, while you dump them from the SSD/card

slimRAW is a fast CinemaDNG compressor. It converts uncompressed CinemaDNG raw video to losslessly compressed CinemaDNG. Lossless compression does not affect image quality - the losslessly compressed raw video output of slimRAW is exactly the same after decompression as the original uncompressed video. slimRAW saves storage space and reduces storage bandwidth requirements for CinemaDNG raw video production. Losslessly compressed CinemaDNG raw video is compatible with various popular video production software.

slimRAW is available for Microsoft Windows and Apple OS X.

It is available now: http://slimraw.com/