BitShares Forum

Main => General Discussion => Topic started by: hughmanwho on October 17, 2014, 08:21:11 pm

Title: When did work on DPOS start?
Post by: hughmanwho on October 17, 2014, 08:21:11 pm
I'm just curious what's the story behind it's invention and how long has it been working?

Also, how does it work from a technical point of view?

Thanks!
Title: Re: When did work on DPOS start?
Post by: testz on October 17, 2014, 08:24:48 pm
I'm just curious what's the story behind it's invention and how long has it been working?

Also, how does it work from a technical point of view?

Thanks!

Please read about this at the wiki:
http://wiki.bitshares.org/index.php/DPOS
http://wiki.bitshares.org/index.php/The_History_of_BitShares
http://bitshares.org/delegated-proof-of-stake
Title: Re: When did work on DPOS start?
Post by: toast on October 17, 2014, 08:37:42 pm
It was invented immediately after I visited Dan for spring break last March and I got to hear a lot of the process of inventing it.

Dan was still thinking in terms of TAPOS and faced the challenge of selecting block producers for short-term security (the chain is ultimately secured by stake-vote via transactions approving what they think the state is). There was a plan to develop a ripple-style consensus algorithm called Unity, and we considered just using a Trustee (timestamper) for TAPOS. The problem with both is that you can't easily replace the master nodes.

The key insight is that CDD applied to a particular block is the same as that piece of stake voting on each block from that chain as it sees it. If your stake can be delegated to a single block signer then old-fashioned DPOS provides the same security as TAPOS with 1% stake voter turnover per block. I think with approval voting that DPOS no longer has the same security properties as TAPOS in terms of stake-vote influence anymore, I think it's possible it could be strengthened by layering TAPOS on again.
Title: Re: When did work on DPOS start?
Post by: arhag on October 17, 2014, 11:29:43 pm
If your stake can be delegated to a single block signer then old-fashioned DPOS provides the same security as TAPOS with 1% stake voter turnover per block. I think with approval voting that DPOS no longer has the same security properties as TAPOS in terms of stake-vote influence anymore, I think it's possible it could be strengthened by layering TAPOS on again.

Can you clarify what you mean here?

I have been a fan of layering TaPOS on top of DPOS for a while now, but not in terms of changing how the consensus chain is determined. The reasons I want it are:
Title: Re: When did work on DPOS start?
Post by: eagleeye on October 19, 2014, 05:23:59 am
If your stake can be delegated to a single block signer then old-fashioned DPOS provides the same security as TAPOS with 1% stake voter turnover per block. I think with approval voting that DPOS no longer has the same security properties as TAPOS in terms of stake-vote influence anymore, I think it's possible it could be strengthened by layering TAPOS on again.

Can you clarify what you mean here?

I have been a fan of layering TaPOS on top of DPOS for a while now, but not in terms of changing how the consensus chain is determined. The reasons I want it are:
  • It is a prerequisite to my implementation (https://bitsharestalk.org/index.php?topic=9452.msg123045#msg123045) of delegate proposals ratified by shareholder vote.
  • It makes this attack vector (https://bitsharestalk.org/index.php?topic=6584.msg87951#msg87951) impossible (although that attack would be very unlikely to be successful in the current DPOS system anyway).

arhag: wow  +5%