Everyone, including identical twins, has a unique fingerprint. In other words, people's identities are coded at their fingertips. This coding system may also be compared to the barcode system that is used today.
While it is stated in the Koran that it is easy for God to bring man back to life after death, peoples' fingerprints are particularly emphasized.
Note this verse of Koran:
"Yes, We are able to put together in perfect order the very tips of his fingers." [75:3-4]