We rely on secrets such as safe combinations, PIN codes, computer passwords, etc. But so many things happen to lose secretes.
1. Secrets can be lost.
2. Documents get destroyed.
3. Hard disks fail
4. People forget
5. People leave companies,
6. people die...
One way to avoid such problems :-
Divide secret data (D) in to pieces (n)
* Knowledge of some pieces (k) enables to derive secret data (D)
* Knowledge of any pieces (k-1) makes secret data (D) completely undetermined.
Such a scheme is called a (k, n) threshold scheme.
This presentation provides a in depth view of Shamir's Secret Sharing Scheme.