We were discussing identity management with Civic.

It is based on blockchain ledger that enables users to login with their fingerprints.  The availability of a distributed ledger does away with a password database. Civic identity management introduces three new components:
1) a variety of smart contracts
2) an indigenous utility token and
3) new software applications.
 Civic builds a system to enable on-demand, secure and low cost access to identity verification aka IDV. Agencies that perform IDV are called validators, the individual whose identity is verified is called a user and the stamp of approval is called an attestation.  The user's information that is attested is called PII - short for personally identifiable information. This form of improvement enabled Civic to allow users to be recognized merely by their thumbprint while the digital identity was attested.
Attestations can be sold while the PII may not be sold. Civic introduced a token or CVC which is used as a form of settlement between participants for identity related transactions. CVC therefore becomes a currency whose transactions can be specified by the contracts. Civic aims to introduce new services  and improve existing services that can be exchanged for this currency. These services may include personal background checks, blockchain notary services, web monitoring and searches, individual credit reports, peer to peer identity services. The currency facilitates and audits the transactions while the services provide the means for the value paid for. In a way the notion of tokens is used to reward the use of services and are generally accumulated by the user not the service provider or requestor. Blockchain works as the ledger in these cases. The smart contracts are the code executed on the blockchain.  The advantages of using a distributed ledger such as blockchain include the following:
There are no middlemen for transfers and therefore there is little fees and low cost. Moreover the protocol has a rewarding mechanism
The ledger is immutable and its integrity checked and agreed on an ongoing basis. 
All transactions on the ledger are visible to anyone and any transaction done anytime is recorded.
The transactions on the ledger cannot be reversed and are immune from chargebacks. These transactions are as sound as cash transactions.
There is a high degree of privacy for the individual whose transactions are maintained in the ledger. The transaction does not divulge any PII but an individual can easily prove ownership of the entries.
The ledger itself is decentralized and maintained by a community where no one actor can gain enough influence to submit a fraudulent transaction or alter recorded data.
#codingexercise
we were discussing a storage based method of finding sum of products of all combinations.
To make it more compute intensive than storage we could restructure it based on the combine method earlier or as follows(pseudocode):
void CombineIntoProductsBySelectingRfromN(List<int> A, List<int>combinations, int n, int r, int depth, int index) {

  if (index == r) {

    int product = 1;

    for (int i = 0; i < r; i++)

      product = product * combinations[i];

    sum += product;

    return;

  }

   for (int i = depth; i < n; i++) {

    combinations[index] = a[i];

    CombineIntoProductsBySelectingRFromN(a, combinations, n, r, i + 1, index + 1);

    combinations[index] = 0;

  }

}

CombineIntoProductsBySelectingRFromN(a, combinations, n, r, 0, 0);

A = 1,2,3

N = 3

r = 2