Cryptocoins News

I am experimenting with CB’s multisig vault. I was just wondering if there’s anyway to do a hard test on it before I move BC into it? I realize I’m going to get a few comments about alternative wallet solutions, but I’d like to stick with this Multisig vault for now. When loggin into CB there’s no extra step to access the vault. So I never have to enter my pass phrase. So I don’t see a way to test that pass phrase to make sure it works if things go offline. Link to Multisig vault for those unfamiliar. https://www.coinbase.com/multisig?locale=en Thanks

• This BIP defines new layer named (for the greater confusion) witness where fully signed transactions can be placed at the witness layer as a whole. Additionally to normal transactions block (no more than 1MB to not HF older nodes out) layer would contain witness tracer transactions that contain anyone can spend scripts with witness layer transaction ids as an inputs and/or outputs.

• More space for every transaction. Rather than creating special addresses that could use scaling discount, this BIP proposes possibility to use any type of input or output in witness layer.

• Bigger scaling potential. As witness tracer transactions contains transaction ids witness tracer transaction size does not increase if transaction inputs (rare) or outputs (always) refers to same transaction. If transaction uses witness layer inputs only, it is not necessary to include signature in witness tracer transaction allowing to include even more transactions in 1MB block.

• Anyone can spend input/output meaning redefinition. Once BIP activates anyone can spend output MUST reference to the transaction that is valid to be included in block. If transaction input refers to anyone can spend output that was created before BIP activates, no additional verification is needed. If transaction is included in witness layer, anyone can spend usage is not altered.

• Transaction version field reuse. BIP redefines usage of highest byte in four byte transaction version field. If bit 0x01000000 is set transaction MUST NOT appear in block layer, it SHOULD be only be placed at witness layer. If that transaction contains at least one block layer input that requires signature to be spent, signer signs additional witness tracer transaction that contains matching anyone can spend output. Signer MAY additionally choose to include from all to none outputs in witness tracer transaction that would not be moved in witness layer ranging himself from blockchain polluter to all in supporter. If witness tracer transaction does not need to be signed it is up to miner to create witness tracer transaction. In that case miner MAY choose to include from all to none outputs in witness tracer transaction ranging himself from saboteur to all in supporter. It is RECOMMENDED to move all outputs in witness layer so witness tracer transaction contains only anyone can spend outputs. If bit 0x01000000 is not set all outputs MUST point to block layer. If transaction has no outputs associated with witness layer, it is normal transaction included in block.

• Transactions and transaction outputs. Witness tracer transactions contains witness layer transaction ids in inputs and/or outputs. Since witness layer transaction is referenced in witness tracer transaction as a whole, all witness layer transaction outputs are referenced as a whole in witness tracer transaction. If transaction does not spend all balance of dependent transaction witness layer outputs (would happen almost always if dependent transaction had multiple witness layer outputs) witness tracer transaction creator MUST add additional output with remaining balance as sum of unspent witness layer outputs.

• Logic of block and witness pair verification. Any transaction in block layer MUST be valid according to pre BIP activation rules (this enforces soft fork). Witness layer transaction MUST be valid according to modified pre BIP activation with explicit 0x01000000 bit test bypass instruction in transaction version field verification function if applied on blockchain where all non witness tracer transactions are placed on enough sized blocks. Optimised method SHOULD be used. If transaction in block layer contains anyone can spend outputs, it is considered witness tracer transaction. All anyone can spend outputs MUST point to already mined witness layer transactions or yet unconfirmed transactions. There MUST be at least one anyone can spend output that points to unconfirmed transaction. Search is performed for inputs that are not post BIP activation anyone can spent inputs and for outputs that are not anyone can spend outputs. If any found, all found inputs and outputs MUST be found in pointed unconfirmed transactions. Mark these inputs and outputs as paired. For each pointed unconfirmed witness layer transaction sum of all non paired output values MUST match with corresponding anyone can spend output amount. Mark these outputs as grouped. Each witness tracer transaction input MUST be anyone can spend output that points to already mined witness layer transaction. For each pointed already mined witness layer transaction there MUST be nonzero unspent outputs. For each witness layer transaction unpaired input corresponding witness layer UXTO MUST be found and corresponding already mined witness layer transaction MUST be refenced as corresponding anyone can spend input in witness wallet transaction. Mark such input in wallet tracer transaction as touched and recalculate sum of unspent outputs for transaction that was referenced in just now ticked input and additionally mark just iterated input as ticked. Verification of properly spent already mined witness layer transaction output MUST pass (non witness layer inputs are enforced to be valid because any transaction is enforced to be valid in block, no need to validate it again). After iteration completes drop zero results from previously calculated sums of unspent outputs list. Each list item MUST be found as corresponding anyone can spend script output that contains exact transansaction id and amount, mark these outputs as ticked. All inputs and outputs in witness tracer transaction and witness layer transactions MUST be marked as paired or grouped, or ticked. Throw an assertion error if sum of witness layer transansaction fees does not match with witness tracer transaction fee. If one MUST word fails, node rejects block that includes such transaction. If peer rejects faulty transaction due to missing uncomfirmed witness layer transaction, node SHOULD ask other nodes to transmit missing transaction and try to go through this validation logic all over again.

• Witness size limits for one block. Witness layer can grow toward infinite if sender creates huge amount of witness layer UTXOs, corresponding witness tracer transaction would be in same size no matter if one or thousand witness layer UTXOs were created. This creates exponential growth of disk space requirements in a Bitcoin timeline. Adjusting witness size limit algo SHOULD be used that retargets every 2016 block with same maximum relative adjustment limits how difficulty adjusts. Starting max witness size 1MB, minimum max witness size 1MB, maximum max witness size multiples of two times 1MB that SHOULD NOT be above 16MB. If max limit is not set or set too large, we centralise Bitcoin in one database core all over again giving bigblockers too much free space than they actually want.

• Implications for users. Not updated clients will continue to receive and send coins via block layer. Not updated nodes MAY NOT see received coins from updated clients if they explicitly did not force miners to point outputs outside witness layer by unsetting 0x01000000 bit in transaction version. Not updated nodes will not be able to spend anyone can spend outputs properly. If users chooses to update client after BIP activates, never client will reverify BIP affected anyone can spend inputs and outputs and download missing witness layer from other nodes. Updated node owners may promote older nodes to upgrade if they send them coins via witness layer. This trick is not guaranteed in case if miner mines witness tracer transaction that moves all coins outside witness layer.

• Implications for miners. As always soft fork requires all miners to upgrade to not mine on top of invalid blocks. Not upgraded miners may mine invalid blocks if they mess with altered anyone can spend logic. Miners may not able to mine layer witness transactions with coinbase input without hardware upgrade (that hardware would calculate transaction id and block hash for each nonce – actually more complex POW algo that is backwards compactible with current POW algo), miners SHOULD contruct coinbase transactions that do not mess with anyone can spend inputs or outputs. Miners can move their coins in witness layer with another transaction if they really want to do so without cost of creating new miner hardware.

• How do you like block max size increase equivalent and different POW without HF? Feel free to reddit this post without any restrictions. Call this post as a result from Challenge Of Reverse Engineering and annoy opponents that this was from (Bitcoin) CORE developers. Choose CORE or Core, or core.

So……