SPV Simply Explained

In this whiteboard video, I attempt to simply explain SPV (Simplified Payment Verification).

I walk through a simple customer/merchant payment scenario and describe how the merchant would validate they are paid by the customer using SPV before broadcasting their transaction to the network.

#bitcoin #crypto #spv #whitepaper #simplifiedpaymentverification #whiteboard

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[hornerst.catherine]

I fully understood what you were saying...but please get a whiteboard pen that works 100%.

[bridgedora]

Best explanation I’ve seen yet on SPV!

[Anthony-uqve]

Josh. that was great.. Thank you so much for sharing.... all the best!

[CharlesMiller]

This is just the kind of thing I'd like to understand, Joshua - thank you. I still have a question: if the merchant only has access to the block headers (online, as you said) how can they get from that single string of numbers - one for each block in the whole chain - back to each individual UTXO that has been hashed with all the others in that block to make up the header for that block? I suppose it's a question of hashing the UTXO and seeing if the result is one of the block headers. But how can that produce the same result for each of maybe thousands of different transactions in that block? Thanks again ...more like this please!

[monkishrex]

Merkle path to the Merkle root but overall good explanation 👍

[JorgeGarciaMX]

Are you saying that there will still be 1% disputes because you can't verify if theyve spent coin in more recent blocks ?

I think user wallets should be online in todays day and age and wallets should force utxos to have hashes of the latest blocks so that there can't be a chance for disputes?

Do these questions make sense or am I missing something?

[stockrt]

Sound would be much better with a good mic. That would help a lot to make the content presentation even better.

[davidg]

Great explanation and visualization.

Have you thought of mirroring your content to Odysee? LBC I'd obviously more limited than BSV, but I'd be interested in hearing your thoughts on their work as that team is attempting to add some utility to their coins with a business vs just hodling.

[vladnovakovsky]

at 6:26 "Merchant has list of blocks" ... "Given TX hash merchant can check is TX in the block". The question is: Block header contains Merkle root that computed using all transactions in this block. I think it's not possible to check whether transaction is in the block using only header - you need all transactions to recalculate merkle root. Recalculated Merle root can be compared with Merkle root from header. Again - I suspect that ALL transactions are needed to check if given transaction is in this block.

[swaaalla]

1. a light wallet holds the original transaction, the block identification and hashes of the merkle tree that can rebuild that particular transaction in the block.
2. an unspent UTXO is stored in the utxo stack. no need to scan the chain because it is ready to go in the stack.
3. the customer does not send the transaction to the merchant. it always broadcasts it. always. plus it does need the internet.