In Proof-of-Stake, can a block creator fudge the block hash?

3

In Proof-of-Work, a block hash is costly to manipulate (say, wanting the hash to be even, or have the hash of the hash smaller than some number) since there is a lot of computing power put into selecting the right header to produce a valid hash.

I'm wondering - are the block hashes in the various Proof-of-Stake implementations easier to manipulate since the hashes aren't bound by PoW mining? Could a PoS miner spend some computational time to generate many valid blocks and pick one to use, or are there some other constrains preventing block hash fudging?

ThePiachu

Posted 2015-10-12T05:03:51.147

Reputation: 41 594

Answers

3

Absolutely. ECDSA signatures at not unique, they can always be permuted by the signer at will by re-signing with a new nonce. The creator of the block can also choose to reorder or omit transactions to alter the block and then re-sign this to get a new block hash.

Anonymous

Posted 2015-10-12T05:03:51.147

Reputation: 10 054

Does that affect security of blocks/blockchain in PoS systems? Changing a particular block hash, would require recalculating the hashes of blocks on top of it - no? – Albert s – 2016-12-24T01:29:36.650

1This is called "stake grinding" and demolishes the security of PoS systems. – Anonymous – 2016-12-27T21:20:13.673

Asked: 2015-10-12T05:03:51.147

Viewed: 216 times

Active: 2016-03-06T19:14:45.190