What if our own blood was where we store our private key. The DNA code is put through a processor that is scrambled. Once that happens that scrambled data is then converted into a private key from which we can get a public address. That public address is how you can receive payment from others such as your workplace.
next time you go to a coffee shop, a restaurant or simply walk in the street anyone can take a sample of your DNA (saliva on the cup, hair,...) and viola they have all your money.
So when ever you want to purchase something at a store you just prick your finger and boom.
have fun with the blood transmitted diseases...
With the DNA thing, someone might take a hair from your head and steal all your money.
oh so you know this already
With the retinal scanner though, you wouldn't be able to have multiple users for a single address.
bitcoin wallets will become super expensive and big to carry around then. not to mention unsafe.
Facial recognition to verify it is you.
even more expensive, not to mention not perfect.