2014/12/26 PoW (Bitcoin) vs PoS (Peercoin), for dummies
“Raw PoW works by finding hash with specified nonce.
Peercoin uses a timestamp and one of your transactions for this. This means you can’t win with a faster computer, as you can only hash once a second. All is needed is a stake and by having a larger coinage you stand a better chance to find a winning block.
Coinage is bounded between 30 and 90 days. Any unmoved coins will only be valid for minting after 30 days. After 90 days, their coinage is capped and cannot increase.
The hash includes previous blockchain data as well as a timestamp (in seconds). Any computer in the network will check that the timestamp in the new block matches the current time – it can reject the block if this doesn’t match.
So a verbal description of the PoS solution in PPC is:
hash(oldblock, timestamp) < target * coinage”
Source: r/peercoin, nov. 2014