Multibit bloom filters | Bitcointalksearch.org

Goms

sr. member

Activity: 350

Merit: 250

So essentially, Multibit offers more privacy than Electrum. How much is the Multibit fees?
Thanks.

achow101

staff

Activity: 3374

Merit: 6530

Just writing some code

Quote from: nezhurin on September 30, 2016, 05:03:53 AM

Quote from: achow101 on September 29, 2016, 05:30:30 PM

Quote from: nezhurin on September 29, 2016, 04:06:06 PM

Quote from: achow101 on September 29, 2016, 03:26:34 PM

How Bloom filters for Bitcoin work are defined at https://github.com/bitcoin/bips/blob/master/bip-0037.mediawiki. They must be used by default with Multibit otherwise the wallet wouldn't be an SPV client.

So if I understand correctly it doesnt make a request with only the address that is personally being used but it downloads the entire last block(?) and it check if the transaction is found?

No. It tells the peer to set a specific bloom filter. That filter means that if any part of a transaction (hash, outputs, inputs, etc) matches that filter (i.e. do some operations with the filter and if it matches one thing should return and if not, a different one). If there is a match, it will relay that transaction to multibit, otherwise it will not. Multibit then has to check the transaction itself to see if it pertains to the wallet. Bloom filters have the effect of having false positives but no false negatives. That means that every transaction that the peer relays to Multibit may not actually pertain to the wallet, but the wallet will receive every transaction that pertains to it.

So does it offer any privacy at all?
The guy running multibit node for getting balances of address is he able to see what IP address looked up which address or no?

A person running a peer that multibit connects to is able to see which transactions are relayed to which peer. So, it is possible for that person to know which transactions were sent to your multibit wallet. However, because bloom filters include false positives, it is not possible for him to know exactly which transactions actually belonged to you. He just knows that some of the transactions relayed to you are actually yours.

nezhurin

newbie

Activity: 16

Merit: 0

Quote from: achow101 on September 29, 2016, 05:30:30 PM

Quote from: nezhurin on September 29, 2016, 04:06:06 PM

Quote from: achow101 on September 29, 2016, 03:26:34 PM

How Bloom filters for Bitcoin work are defined at https://github.com/bitcoin/bips/blob/master/bip-0037.mediawiki. They must be used by default with Multibit otherwise the wallet wouldn't be an SPV client.

So if I understand correctly it doesnt make a request with only the address that is personally being used but it downloads the entire last block(?) and it check if the transaction is found?

No. It tells the peer to set a specific bloom filter. That filter means that if any part of a transaction (hash, outputs, inputs, etc) matches that filter (i.e. do some operations with the filter and if it matches one thing should return and if not, a different one). If there is a match, it will relay that transaction to multibit, otherwise it will not. Multibit then has to check the transaction itself to see if it pertains to the wallet. Bloom filters have the effect of having false positives but no false negatives. That means that every transaction that the peer relays to Multibit may not actually pertain to the wallet, but the wallet will receive every transaction that pertains to it.

So does it offer any privacy at all?
The guy running multibit node for getting balances of address is he able to see what IP address looked up which address or no?

achow101

staff

Activity: 3374

Merit: 6530

Just writing some code

Quote from: nezhurin on September 29, 2016, 04:06:06 PM

Quote from: achow101 on September 29, 2016, 03:26:34 PM

How Bloom filters for Bitcoin work are defined at https://github.com/bitcoin/bips/blob/master/bip-0037.mediawiki. They must be used by default with Multibit otherwise the wallet wouldn't be an SPV client.

So if I understand correctly it doesnt make a request with only the address that is personally being used but it downloads the entire last block(?) and it check if the transaction is found?

No. It tells the peer to set a specific bloom filter. That filter means that if any part of a transaction (hash, outputs, inputs, etc) matches that filter (i.e. do some operations with the filter and if it matches one thing should return and if not, a different one). If there is a match, it will relay that transaction to multibit, otherwise it will not. Multibit then has to check the transaction itself to see if it pertains to the wallet. Bloom filters have the effect of having false positives but no false negatives. That means that every transaction that the peer relays to Multibit may not actually pertain to the wallet, but the wallet will receive every transaction that pertains to it.

nezhurin

newbie

Activity: 16

Merit: 0

Quote from: achow101 on September 29, 2016, 03:26:34 PM

How Bloom filters for Bitcoin work are defined at https://github.com/bitcoin/bips/blob/master/bip-0037.mediawiki. They must be used by default with Multibit otherwise the wallet wouldn't be an SPV client.

So if I understand correctly it doesnt make a request with only the address that is personally being used but it downloads the entire last block(?) and it check if the transaction is found?

achow101

staff

Activity: 3374

Merit: 6530

Just writing some code

How Bloom filters for Bitcoin work are defined at https://github.com/bitcoin/bips/blob/master/bip-0037.mediawiki. They must be used by default with Multibit otherwise the wallet wouldn't be an SPV client.

nezhurin

newbie

Activity: 16

Merit: 0

From what I understand in this case it wont matter that the user IP is exposed since when multibit will try to get balance of your address it will in the sametime try to get balance of other addresses that dont belong to you is my understanding of bloom filters good? and are they enabled by default

Topic: Multibit bloom filters (Read 765 times)