VIP191 is the implementation of the proposal submitted by Totient Labs to improve the existing Multi-party Payment Protocol (MPP) of VeChainThor blockchain. By expanding the signature field to contain an additional delegatorSignature concatenated with the sender signature, VIP191 allows someone other than the sender to co-sign a transaction in order to pay for the transaction fee, also known as a Designated Gas Payer. This improvement is going to broaden the use cases of the fee delegation feature and bring the answers to some of the questions such as:
How to sponsor a specific operation which calls multiple contracts in a more flexible manner?
How to sponsor multi-clause transactions where each clause is to a different contact?
While the MPP feature has been instrumental in building the first wave of applications on VeChainThor, we are actively engaged in growing use cases and scenarios, and glad to confirm that in the latest release v1.1.0 VIP191 will be activated at block #2,898,800 (~ Tue, 28 May 2019 04:00 GMT) on the VeChainThor testnet. VIP191 activation on mainnet will occur after the test is concluded and identified vulnerability (if any) is remediated.