Komodo Platform uses a unique mechanism to secure its blockchain and all side-chains. The mining algorithm is known as dPoW and it recycles Bitcoin's hashrate by storing blockchain data directly onto a distributed ledger with stronger hashrate (i.e. Bitcoin). In essence, this provides a second layer of protection since the protected chain may also rely upon its own PoW or PoS hashrate.
The process of storing the data onto the chain with stronger hashrate was coined by Komodo as a "notarization". Each notarization represents a transaction on the stronger chain. However, these transactions contain hashed information which is inserted via OP_CODES such as OP_RETURN.
Each notarization has a cost. Currently the cost of a notarization on Komodo amounts to roughly 100 KMD annually. ChainZilla will implement a second layer of notarization which will be more cost effective without sacrificing security.
A notarization contains a hashed checksum of the previous known block. This provides an "anchor" for the side-chain and it effectively recycles Bitcoin's and Komodo's hashrate to secure all blockchains with lower hashing power.