Electrum - Bitcoin client for the common users (friendly and instant)

[Tachikoma]

He can't see the closed/assigned issues and the comments on the issues? My bad.

[SomeWhere]

He can't see the closed/assigned issues and the comments on the issues? My bad.

Why all the animosity? Spread the love!

Your pre-poster is right - I signed up to github just to post this, so I'm not exactly an experienced user. Even with closed bug reports, it could be that the response on github is a lot slower than on the forum, so I was just asking to know where I should rather post in the future. I plan to stick around for a while.

[Tachikoma]

Don't mind me, I am only human and sadly affected by moods. 

Issues are indeed being taken care of as soon as a developer is able to :}

[SomeWhere]

Oh, and before I forgot: I love the client. It's exactly the kind of usability the average consumer will need.

[molecular]

Oh man, I think my wallet got screwed up again:

Code:

nick@blackbox ~/bitcoin/electrum $ ./electrum history
Connected to electrum.novit.ro:50001
Exception in thread Thread-2:
Traceback (most recent call last):
  File "/usr/lib64/python2.7/threading.py", line 551, in __bootstrap_inner
    self.run()
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 1277, in run
    self.synchronize_wallet()
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 1227, in synchronize_wallet
    new_addresses = self.wallet.synchronize()
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 388, in synchronize
    new_addresses += self.synchronize_sequence(self.change_addresses, self.gap_limit_for_change, True)
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 376, in synchronize_sequence
    if map( lambda a: self.address_is_old(a), addresses[-n:] ) == n*[False]:
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 376, in <lambda>
    if map( lambda a: self.address_is_old(a), addresses[-n:] ) == n*[False]:
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 364, in address_is_old
    tx_age = self.verifier.height - tx_height + 1
AttributeError: 'NoneType' object has no attribute 'height'

why does this always happen to me?

maybe because I'm running electrum --gui=qt at home and then, in parallel, am using the cmd-line version remotely as seen above? (this usually works just fine)

[Tachikoma]

That really should not matter. Which version of electrum is this?

[molecular]

Was just going to report my freshly git-pulled client wouldn't syncronize (restart and selected other servers for half the day now), when it suddenly worked.

I noticed an exception on startup (when it didn't work), which didn't occur when it worked.

Code:

Exception in thread Thread-3:
Traceback (most recent call last):
  File "/usr/lib64/python2.7/threading.py", line 551, in __bootstrap_inner
    self.run()
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 1203, in run
    self.wallet.receive_history_callback(addr, result)
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 615, in receive_history_callback
    if not self.check_new_history(addr, hist):
  File "/mnt/maui/home/nick/bitcoin/electrum/lib/wallet.py", line 1045, in check_new_history
    for o in tx.get('outputs'):
AttributeError: Transaction instance has no attribute 'get'

[ThomasV]

Was just going to report my freshly git-pulled client wouldn't syncronize (restart and selected other servers for half the day now), when it suddenly worked.

I noticed an exception on startup (when it didn't work), which didn't occur when it worked.

Thanks for the report, I fixed it.
There has been important changes in the code lately, but this is almost finished.
Next week will be for testing.

[SebastianJu]

How (un)safe is electrum when used at an public wlan? I remember something about a risk with portable version but i dont remember what it was...

[Tachikoma]

No real private data is exchanged so it should be safe I would recommend switching to a SSL server so your communication can't be spied on regardless. 

[stepkrav]

May i create a watch only wallet with electrum client ? Thanks for developping this software.

[Tachikoma]

Yes. Restore your wallet from your master public key and it will be de-seeded, so watch only.

[SebastianJu]

No real private data is exchanged so it should be safe I would recommend switching to a SSL server so your communication can't be spied on regardless. 

For doing so i only chose a server and switch to TCP/SSL? The port changes then but when i click the server again the connection type is set back. So i dont know for sure that i run a secure connection.
How is security with HTTPS in comparision?

And regarding anonymity... my ip will remain anonymous with electrum right? I remember the CCC found out some addresses of wikileaks through blockchain. Thats not possible with electrum because i go through a server right?

[BkkCoins]

No real private data is exchanged so it should be safe I would recommend switching to a SSL server so your communication can't be spied on regardless.  

For doing so i only chose a server and switch to TCP/SSL? The port changes then but when i click the server again the connection type is set back. So i dont know for sure that i run a secure connection.
How is security with HTTPS in comparision?

It sounds like it's not connecting with SSL. You should try some other servers and see if it's just one or all that are behaving like that. HTTPS should be similar to SSL security wise.

And regarding anonymity... my ip will remain anonymous with electrum right? I remember the CCC found out some addresses of wikileaks through blockchain. Thats not possible with electrum because i go through a server right?

Electrum servers do have logging that records your IP. So whether that could be tracked is dependent on the log handling of each server admin. I know mine is kept for a few days before it gets rotated out. Also, an admin may or may not be easy to force into providing that info.

If anonymity is important to you then using a Tor service Electrum server is a better choice. A couple admins do operate them. See this forum's other threads for info. Installing and using Tor is fairly easy to do. After you have Tor installed you choose the SOCKS5 proxy mode in Electrum with localhost and Tor port#, and enter the onion address to connect.

[SebastianJu]

Thanks for the answer. Anonymity isnt that important to me when one would have to go to the server first to find my address. Or can it be found through blockchain somehow like CCC did?

When i chose a server, switched to TCP/SSL, click ok and then go back to server and the setting is still this way can i be sure then that it runs through SSL? Im not sure how to find out really.

And with this setting using an open wlan isnt problematic right?

[BkkCoins]

Thanks for the answer. Anonymity isnt that important to me when one would have to go to the server first to find my address. Or can it be found through blockchain somehow like CCC did?

The blockchain itself does not store any IP values but services like blockchain.info store and report the IP of the node that a transaction is relayed by. In this case that would be the server IP not yours.

When i chose a server, switched to TCP/SSL, click ok and then go back to server and the setting is still this way can i be sure then that it runs through SSL? Im not sure how to find out really.

This sounds right but I'd be careful of failover mechanisms as this is a bit unclear. If you select the "choose random server when failed" option it could be it will connect to anything available even not using the same protocol you expect. So you may want to not choose that option to be sure you manually intervene if a server is offline.

And with this setting using an open wlan isnt problematic right?

Generally data is safe over SSL/HTTPS but if you are on a public (untrusted) network then you are still vulnerable to any other attacks possible. eg. an ARP spoof attack can redirect traffic such that a MITM attack can be setup, meaning you may not trust you are connected to who you think, or a DNS spoof attack. On untrusted networks even with SSL/HTTPS it is better to use a VPN or SSH tunnel to connect to a network you trust more. Also, I'm not sure how much certificate validation is done in the client for SSL and/or HTTPS. I do know that my server has a self-signed certificate and it seems to work ok - which implies that identity is NOT checked by the client. So while data in transit is secure you cannot be sure who you are connected to. The case could be made this doesn't matter so much as you do not need 100% trust for the server anyway, but be aware if your transactions are super secret that some hostile entity may be able to fake being the server.

[bitcats]

The blockchain itself does not store any IP values but services like blockchain.info store and report the IP of the node that a transaction is relayed by. In this case that would be the server IP not yours. be able to fake being the server.

And the server stores my IP?

[bitcats]

Yes. Restore your wallet from your master public key and it will be de-seeded, so watch only.

I can restore my wallet from the master public key? Will the imported addresses be included then?

[Tachikoma]

The blockchain itself does not store any IP values but services like blockchain.info store and report the IP of the node that a transaction is relayed by. In this case that would be the server IP not yours. be able to fake being the server.

And the server stores my IP?

The Electrum server stores an IP address from a client in it's log. Those logs can be rotated but this all up to server operator.

Yes. Restore your wallet from your master public key and it will be de-seeded, so watch only.

I can restore my wallet from the master public key?? Will the imported addresses be included then?

You can restore your wallet from MPK to create a deseeded wallet. No, imported addresses are not part of the deterministic wallet and won't be included.

[Tachikoma]

I don't think importing just public keys is possible at this moment.