Bitcoin Forum

Is there any SPV client with the same wallet functionality as Armory? I took a look at Electrum and Multibit, but they're both missing some features I need.

What features are you looking for?

Bumping this thread because I like Armory's fragmented backup, but I just cannot devote 80 Gb of disk for blockchain + Armory cache. I tried Electrum's multisig, but I don't understand it: I need to add other signers' master key.

Most, if not all, SPV wallets are based on seeds... You can fragment that seed. As for fragment security I'm not sure what would be possible to do. Maybe hash the seed? Or maybe scramble the words.

No. You can't have the same functionality (extremely high security) with a SPV client.

I read that SPV has security issues but I failed to understand them. The only thing that could happen is to lie about transactions, but in any case your money won't disappear. Can you give me an example of an actually damaging situation coming for the use of SPV? I understand that using an SPV means not doing our share at strenghtening the network, which has a impact of the security as a whole but I'd like something more down to earth.

Well..you need two devices(either windows/linux/os x)at the creation of the multisig wallet you will get a seed that you need to write down for backup and after that you get 1 xpub key that you need to export(as in write it to other device) and from both xpub key a multi signature wallet will be created(every outgoing trasanction will have to be signed by both devices,at least one of them need to be connected to the internet)

Sorry, I've never had any significant reason to concern myself with such things. (If I use a SPV client, it's for pocket change.)

Off the top of my head, the recent (a few months back) multi-block fork during which some SPV clients were on the "wrong" chain comes to mind. I certainly wouldn't want my client telling me something which later turns out to be different. While the situation may not turn out to be directly damaging as far as a user's funds go, confusion itself can certainly lead to various problems resulting in actual damage.

But that is not the case for Electrum since is not truly an SPV wallet,because it only connects to electrum servers not bitcoin nodes(and altcoins such as Bitcoin XT)
Same could be told about a couple mobile wallets(such as Mycelium)that connects to a couple of centralized nodes and which are less affected by what you described and a couple of sybil attacks that ("real")SPV wallets are affected by it