This is my projrct at Insight where I was a Decenteralized Consensus Fellow in Fall 2020. I developed a bitcoin wallet that checks the randomness and remove keys with less entropy. There are different kind of bitcoin wallets out there like paper wallets, Mobile app wallets and hardware wallets, but one thing that is common in all of them is that they are all contain keys not coins; it is actually more like a keychain.
The keys are used to track ownership, receive and spend bitcoins. The Keys are nothing but some random 256-length binary sequences.