Or do need to download the entire blockchain?
Well, you can run mining in simplewallet but it has to be a local node, public nodes do not allow mining.
https://github.com/Karbovanets/papers/blob/master/SPOW.md
and
https://github.com/Karbovanets/papers/blob/master/KIP-001.md
with
https://github.com/Karbovanets/papers/blob/master/blodha.md
or TLDR:
- custom yespower hashing algo with blake-256;
- Signed Proof-of-Work (SPoW) - The main idea behind SPoW is to sign header data with the private key of the miner receiving the reward for the block. Because nonce is included in the signature, we assume that pooled mining will be hard to organize as pool operator can not outsource this to workers;
- Blockchain-dependant Proof-of-Work "BloDHA" - it's based on the idea to include the data from blocks, the heights of which are defined as an intermediate result of a preparatory hash. That is, for the next hash with another nonce these intermediate blocks will be completely different. Moreover, iterations prohibit requesting the data from a remote node. Thus, without access to the blockchain hashing is not possible, which means that only full nodes are able to mine.
and bolded out fragment explains why you need a local node.