<p>The merkle tree means that you can verify the existence of a transaction in a block while only having the header, the transaction, and the merkle tree itself. It allows SPV clients to act extremely quickly and securely while only using the bare minimum of bandwidth. MultiBit is a SPV client that works in this way, and is extremely quick as a direct result. </p>

CC BY-SA 3.0
2013-12-09T10:55:51.643Z
thanks. spv uses bloom filters and the merkle paths within the relevant blocks to prove that the transactions specified by the peer really did occur as claimed. however i'm asking if this is the only way that merkle trees are used in bitcoin? ie are merkle trees only ever used _within_ a block and never across more than one block, for example?
mulllhausen
CC BY-SA 3.0
2013-12-09T11:04:31.173Z
Not at the present, the transactions within a block are the only place I'm aware of that Merkle Trees exist.
Anonymous
CC BY-SA 3.0
2014-02-07T11:16:53.587Z
Actually you only need the branch for your transaction and not the whole tree.
Luca Matteis
CC BY-SA 3.0
2013-12-09T07:55:55.513Z
2013-12-09T07:55:55.513Z
Anonymous
<p>as i understand it, merkle trees are useful for operations within individual blocks, but do they have any use outside of each block? for example, are the merkle-roots from each block ever used in combination for any other purposes such as blockchain validation?</p>

<blockchain><merkle-tree>
do transaction merkle trees have any use outside individual blocks?
mulllhausen
# do transaction merkle trees have any use outside individual blocks?

(Asked by: username_0 on 2013-12-09)

as i understand it, merkle trees are useful for operations within individual blocks, but do they have any use outside of each block? for example, are the merkle-roots from each block ever used in combination for any other purposes such as blockchain validation?

**Tags:** blockchain, merkle-tree


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## 1 answers

### Answer by username_1 on 2013-12-09. Score: 2

The merkle tree means that you can verify the existence of a transaction in a block while only having the header, the transaction, and the merkle tree itself. It allows SPV clients to act extremely quickly and securely while only using the bare minimum of bandwidth. MultiBit is a SPV client that works in this way, and is extremely quick as a direct result.

> **Comments:**
> **username_0**: thanks. spv uses bloom filters and the merkle paths within the relevant blocks to prove that the transactions specified by the peer really did occur as claimed. however i'm asking if this is the only way that merkle trees are used in bitcoin? ie are merkle trees only ever used _within_ a block and never across more than one block, for example?  
> **username_1**: Not at the present, the transactions within a block are the only place I'm aware of that Merkle Trees exist.  
> **username_2**: Actually you only need the branch for your transaction and not the whole tree.  

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