---
# System prepended metadata

title: 'PPCoin: Peer-to-Peer Crypto-Currency with Proof-of-Stake'
tags: [PoS, '*', Energy, '2012', P2P, TT]

---

# PPCoin: Peer-to-Peer Crypto-Currency with Proof-of-Stake

###### tags: `PoS`, `*`, `2012`, `P2P`, `Energy`, `TT`

## Summary
PPCoin(peercoin) has a hybrid design including both PoS and PoW blocks. To be able to generate a block, a node has to destroy it’s coin age(coin quantity x time) thus limiting the search space(unlimited for PoW). They claim that in the long term, the PoW mint rate will approach zero which will lower the energy consumption significantly.  However blockchain history and transactions are protected by a centrally broadcasted checkpoint.
## Comments
The paper itself is really optimistic but it’s dated 2012 and doesn’t have much references.
More information can be found at: https://university.peercoin.net/#/1-introduction
The low energy consumption thesis is still not detailed. 
