Bitcoin Forum

I would like to hear your opinions: I heard electrum is a lightweight and fast wallet to execute BTC transactions. Is the wallet safe to use?

Alternatively, I have to keep a blockchain in my computer that is 50 gigabytes

It's most like blockchain, and yes its safe.

Electrum is safe, fast and efficient, it uses servers which index blockchain so you do not need to worry about freaking huge blockchain filesizes. You can import private keys to a privatekeys only wallet or create a seed wallet. It allows you to receive and send bitcoins using email addresses too, although I would not recommend it. It also allows alot of different wallet types, multisig, 2fa or hardware based.

However, despite all the benefits..Any wallet is only good if your computer is clean in the first place

Thanks! But if the electrum software gets updated, what will happen to my bitcoins? Do I have to use download the latest electrum to keep my bitcoins?

bitcoins aren't physical things... Basically, a wallet is just a piece of software to manage your private keys, generating transactions, broadcasting.
If electrum updates, nothing happens. You either chose to install the update or not (which usually goes seamingly, and if it goes wrong, you just use the seed words you wrote down when you first installed electrum, and restore your wallet... The worst thing that'll happen is the fact that you lost your labels).
If you chose to run an outdated version, you won't have access to the latest bugfixes, patches and new features, but usually,it's not a real problem.

PS: I'm also a big electrum fan. Core might be a tad bit better, since you synced and verified the full blockchain, but electrum is still good, since your private keys don't leave your computer, and can be encrypted with a strong password and 2fa

For most updates altcoinhosting is correct. There have been a few exceptions in the past. They have been due to bitcoin network changes which required a new electrum version. You will usually get some error when something like this happened and you try to send some coins. If you ask in the electrum section[1] you usually get a good and quick answer, esp. when there is a required patch due to network changes.


Electrum is nothing like "blockchain". For one what do you mean with "blockchain"? The service blockchain.info? If so, its a service that can go offline and fail you (as it has in the past), whereas electrum is a local wallet. Yes, electrum requires an electrum server. These are run by the community and even if all should fail you, you can still export your private keys into a different wallet.

If you are refering with "blockhain" to the blockchain, the database where all bitcoin TX are stored, electrum is nothing like that either. Its a wallet.

[1] https://bitcointalk.org/index.php?board=98.0

Oh.. okay. So your bitcoins are technically not stored on your computer, but it is virtually in cyber space but you control the private keys to gain access to it and electrum is simply the software that helps you to interact with your bitcoins that are some where in cyber space.

On a technical level, there are actually no such things as a Bitcoin. There are only outputs. The private keys allow you to spend certain types of outputs, pay-to-pubkey and pay-to-pubkey-hash, which are the most commonly used and "standard" output types. There are also no addresses on the technical level.

Electrum is a good desktop wallet, even better when used with a Trezor so your private keys are always kept offline.

I just installed it. The original wallet takes ages and centuries to load so i decided to give electrum a try. I will use it for loading my paper wallet balance. It looks safe enough, offers 2FA. But right now i don't trust anything which connects to internet when it comes to crypto coins so i think i will transfer my funds back to my paper wallet after i make my purschases.

I do not know if it is worthwhile to invest in a hardware based Trezor wallet at the moment as I am still exploring how bitcoins work.

Fair enough. If you have a full bitcoin you need a hardware wallet. Ledgers are less than $30 if Trezor is too spendy for you. Your explorations should include a look at hardware wallets also.

If you have an extra older laptop not being used and you can leave disconnected from the net you can do cold storage the old way using Electrum cold storage (http://docs.electrum.org/en/latest/coldstorage.html). Not used much nowadays since hardware wallets are cheap and more convenient, also work with your phone.

Does everyone keep a cold wallet? Looks to be a lot of hassle if a person do not store a lot of coins.

I can only speak for myself, but i do have both a hardware wallet and paper wallets.
When i had just a very small ammount (like $50-$200 worth of BTC) i only had paper wallets, but after i got around 1BTC, i decided to go for a hardware wallet. It was a great investment. They start at less than 20 bucks for the cheapest one.

btw: a paper wallet isn't that much of a hassle to generate. You do have to follow the correct procedure to generate one safely. If you just open bitaddress.org on an unsecured, online computer where you've installed a lot of cracked software, run the generator while online, create an unencrypted paper wallet, print it over wifi and keep a pdf copy on your pc, you're probably better off installing core, electrum or multibit. If, on the other hand, you follow the correct procedure, paper wallets are really safe, and really cheap to make :)

Electrum is the safest of all online wallets , its a local desktop wallet which relies on internet connection. However for it to be safe you need a clean PC at first, although I have done a test, installed a new electrum in my work PC which I know is infected, and put some bitcoins in it, they are still there, so a pretty nice wallet out there. As long as you have the seed and you have quite a lot of bitcoins, you can go to Bahamas for vacation and open it from there with the seed :) . Definitely the best of all online wallets and desktop ones.

I agree that Electrum is easy to use and it is lightweight. Other wallets are confusing and slow. Electrum for me then :)

Thank you everyone.

But how to find out the private keys here.  Is it same as seed?

Electrum is just a perfect bitcoin wallet, has a low size and your pc won't keep syncing 50Gb as you mentioned, it is pretty fast and doesn't need any special requirements.
It can be combined with hardware wallets as well like trezor but keep in mind to save the seed, wallet file and password in a safe place.

No the seed is different from the keys. If you go to the address tab and rightclick on an address you can let the wallet show you its private key.

Ok.

Is it okay if I just save wallet, seed and password in pendrives in a safe place rather than saving private keys?

Saving the seed is the most important thing. You can use it to make a new wallet that doesn't have a password if you lose your original password. However, there's no harm in backing up the wallet and password too.

Make multiple backups on multiple types of backup media in case one gets corrupted, and make sure they work before relying on them. Pen drives can stop working, DVDs can get broken. If you have backups on a pendrive, DVD, and memory card then if one of them gets broken you can still use the others. No one backup media is 100% reliable.

Yes, I agree.  I have 3 backups, one in another PC, one Memory card (inside USB data card) and one Pen drive.

When you say "Saving the seed is the most important thing. You can use it to make a new wallet that doesn't have a password if you lose your original password. However, there's no harm in backing up the wallet and password too," will it mean we can restore our wallets that way also?

Also, I know seed and private keys are different things.  Saving private keys are important because if desktop wallet stops functioning or site goes offline and can so the offline wallet, we can still recover from address and private key.  I think I am correct here but still I am Newbie so not exactly 100%.

Besides restoring from seed you can also restore from a backed up wallet file and password. However,wallet files can sometimes get corrupted, and you can generate a new uncorrupted one using the seed.

Electrum can use the seed to generate an almost unlimited number of addresses and corresponding private keys. Each time you send coins from one address it sends the change left over to a new address by default. If you only have a few private keys backed up, then make a lot of transactions most of the change left over could get sent to new addresses which you haven't backed up.

There is an electrum setting that forces your wallet to send left over change back to the address you sent from, but you have to manually change the settings to make your wallet do that. If you don't alter the "out of the box" settings your wallet will send change to a new address after every transaction.

But unfortunately, I have saved private keys of only one address where all of my coins are in Electrum.  I have Encrypted with password also.  Isn't it fine? How to fully decrypt (to encrypt later) and save private keys of other addresses in Electrum?

Back up your seed first. You can use that to get all the private keys and addresses your wallet will ever make.

Click wallet in the menu, then seed in the drop down list, and your wallet should show you its seed.

https://i.imgur.com/QqHMA5s.png

You can get the private key of any address by clicking the addresses tab, then right clicking an address you want, and selecting "private key" in the list that appears.

Another question:  What will happen if Electrum just disappears (software stops functioning or Electrum people just stops the project), can I still use my coins saved in Electrum with private key and addresses?

Stop mucking about with individual private keys. The seed is all.

Electrum is software. How do you imagine it will disappear? It is hosted on github. It is installed on countless computers around the world. All that will disappear?

If it all disappears then you still need a record of the algorithm they use to convert seed mnemonic into master private key. That algorithm is the same as the one for bip39 AFAIK. bip39 is also hosted on github and is found in countless other wallet software. I guess that could all disappear too in whatever world ending event causes electrum to vanish.

I just wanted to know what will happen if we all find it impossible for transaction to take place with Electrum, we could see the coins in Electrum but unable to send (or even receive) with Electrum.  I am New and so this may be a stupid question.

Electrum has no control over what other people do with their money so it can never stop you from receiving bitcoins. If you ever find yourself unable to spend your money then you can ask for help here or try and figure it out yourself (usually upgrading to the latest version fixes bugs). If nothing works then you will have to recreate the individual private keys from your seed and use another bitcoin client to spend your money. That is explained in the last paragraph of my answer above.

Yes. much better than multibit. The thing I like is I get a seed phrase to use as a recovery incase my HD crashes. Already had to do this twice. The plugins are nice too, like syncing notes/descriptions for transactions, although this may not be very private....but I'm guessing if you want a hosted blockchain wallet then you don't mind

Nope... sadly it isn't... Electrum uses their own proprietary seed to master private key algorithm. :-\

ThomasV has his reasons for this: http://docs.electrum.org/en/latest/seedphrase.html


However, the advice given above is still sound... make sure you have a backup of your seed... that is the whole point of HD wallets. You don't need to worry about backing up wallet files or private keys or passwords. You just need your seed.

But what if you would want to change to a different piece of Bitcoin software that does not use seeds?

I'm not sure why you would want move to a non-HD wallet, but iff you're switching to another app that doesn't use seeds... you can very easily export your private keys from Electrum. You don't need to be running the latest version, or for the Electrum network to be running to do this.

It is also possible to make a couple of minor modification to the BIP39 Mnemonic Code Converter webpage (https://iancoleman.github.io/bip39/) and it will convert the Electrum mnemonic into addresses and private keys. Basically, I just disabled the phrase validation (it always returns true) and changed the default Passphrase from "mnemonic" to "electrum"... the page then outputs the same addresses/keys as generated by Electrum

What is the correct website to the electrum since there are lots of phishing site everywhere ... I just created a new email mailnly for my wallet only ... So I don't want to sign up in any phishing site... Thanks pls anyone help

You don't need an email address for Electrum. It is not a "web wallet"... You don't "sign up" for anything. It is a desktop software wallet that runs on you PC (Windows or Linux) or your Mac... There is also an Android version, but it is feature limited.

Anyway, the official Electrum website is: https://electrum.org/#home

After reading through all the posts of this thread, I guess I should have Electrum installed.
Bitcoin core is way too heavy.

Electrum is an open source wallet, You can see the code behind this wallet here: https://github.com/spesmilo/electrum
I assume that any wallet built from this source code is secure to use. Make sure your PC is clean.

Based on the reviews above it looks like Electrum is a good thin wallet for Bitcoin.

Is there a similar wallet for Ethereum?

Electrum wallet cannot be used to store Ethereum, Unfortunately it only support Bitcoin, Bitcoin Cash (Fork).
for similarities, I will only recommend you this web wallet, myetherwallet.com

Thanks for advice! Web wallet means that my private key will be stored on smb's server vs. my PC as it's the case with Electrum. I am looking for a thin Ethereum wallet which stores private key on my PC.

If I store bitcoin in electrum wallet, can I claim future bitcoin forks?
I heard there will be some fork happening in Decemeber.

The golden rule has always been... You need to have access to the private keys to ensure access to fork coins...

Electrum gives you access to private keys... So the short answer is "yes, with a couple of conditions".

Those conditions would be that Electrum MultiSig and/or 2FA wallets have historically been problematic when it comes to accessing fork coins.

SegWit wallets are likely to be just as problematic.

My advice, if you're planning on holding coins in Electrum for the purposes of getting access to fork coins is to use a "legacy" (aka. NON SegWit) standard wallet (Generated addresses should start with a "1") to reduce the chances of issues when claiming.

Thanks for your explanation and advice.
All my addresses in Electrum start with a "1", and there is a [standard] at the end of the title.
So it must be a  "legacy" (aka. NON SegWit) standard wallet. right?

Based on the information you have provided... yes, it would appear you have a Non SegWit standard Electrum wallet.

Since the wallet.dat file includes the seed, how is it that some transactions could be on addresses not backed up? Eg, one can load the already encrypted wallet file, enter the password, and then can view the seed. Which is what is necessary to generate all the additional addresses. Therefore it is only a temporary problem?

I think he was specifically referring to the user who said that backing up addresses/private keys was a good idea. The issue being that you could get into the situation where you are missing certain addresses/private keys...

Having the seed means you will be covered no matter what. Of course, having BOTH the seed and addresses/private keys is probably "safer"... but really unnecessary. In summary, in my opinion:

Addresses/private keys only = Potentially dangerous
Seed only = Perfectly Adequate
Seed+Addr/Priv keys = Overkill

"News: ♦ Critical vulnerablity in Electrum; SHUT DOWN ELECTRUM IMMEDIATELY and upgrade. Other clients are fine"

https://bitcointalk.org/index.php?topic=2702103.0

There's an upsate regarding Electrum upgrade and I hope they will manage it properly because millions of users won't trust them again. And part of bitcoiners I want to save my bitcoin in electrum wallet.

I opened my Electrum wallet today, January 18, 2007 and found out that on January 2, 2018 all my bitcoins (7.88014412 btc worth $110,682.86 USD) were sent to the following bitcoin address:1BhbPsVryBx9vBwLgaFRg2jY4Y1dh9i5vf

Electrum is claiming to have been hacked and my coins were stored in Electrum and there was no way anyone could access my computer as it stayed offline and powered down until I needed to access my bitcoins.

Electrum Wallets Were Vulnerable and Nothing Was Done For Two Years. My Bitcoins were either stolen from my Electrum Wallet or Electrum just made Billions by claiming they were hacked. STAY AWAY FROM ELECTRUM!!!

Apparently, Electrum knew about the vulnerability in their software for over two years. They are only claiming they knew about the security issue as of November 24, 2017 and did nothing about it until January 7, 2018 which just happens to be 5 days after my coins were stolen.

Electrum never warned wallet owners of the severity of the security vulnerability and after learning about the problem, they were negligent by not releasing a patch, immediately, to fix the problem. If nothing else, they should have at least informed wallet owners to move their coins out until the problem was fixed.

Read more about Electrum's carelessness about security within their software here: https://motherboard.vice.com/en_us/article/ev55na/electrum-bitcoin-wallets-were-vulnerable-to-hackers-for-two-years-json-rpc

I did not have 2FA enabled but I did have a very long password that had to be entered before funds could be transferred. I also have Norton AV installed and no viruses have been found.

Is there any way you can help me get my money back? or anyone you can recommend that can help me track down the owner of this wallet where my funds were sent to, or recommend someone who knows how I can file a lawsuit against Electrum?

http://bitcoinwhoswho.com/address/1BhbPsVryBx9vBwLgaFRg2jY4Y1dh9i5vf
https://blockchain.info/address/1BhbPsVryBx9vBwLgaFRg2jY4Y1dh9i5vf

I can say for sure that EVERY SINGLE case I ever read about how "Electrum stole me" or "Electrum is unsafe" turned out to be the user's fault. EVERY SINGLE ONE OF THEM. I (plus a HUGE part of the community) am using Electrum for over 2 years and I trust them. Even after this security issue, I have never seen a single case where someone lost their funds due to this exploit. So, IMHO that was (probably) your fault.

1. Norton AV can't find every viruses. And if you had a malware, a big password doesn't mean anything.
2. Are you sure that you downloaded the wallet from Electrum.org? I can remember at least 2 cases where the user claimed that he did while he actually downloaded a fake software from electrumwallet.com or something similar.

I don't think so.

That's very unlikely.

Probably just a waste of time.

---

Btw, why aren't you storing over $110k in BTC in a hardware wallet?

Totally feel the Electrum is the safest wallet and that any cases of accounts being compromised is indeed the users' fault... Never had any issues with Electrum or other wallets as a matter of fact.

If you had a password set then there is no way you were vulnerable to the json rpc exploit.

Did you check the hashes when you downloaded electrum to verify that it was authentic?

There are people (maybe researchers, not sure about businesses) who specialize in tracking bitcoin, you could look into contacting one of them. I imagine you could set up an alert on the bitcoin address it was sent to. When it gets sent to another address, and so on, perhaps it could eventually be tracked to an exchange.

If you were offline, how did it get sent? The security vulnerability was apparently related to javascript in a website, were you online when it happened?

I have been using Electrum for some time, since it is much more convenient compared to bitcoin core wallet.
As you said, I set a very strong password. It should be secure enough as long as nobody get my password.

One thing you might consider is loading the Electrum, saving the password and seed words, doing the work you need to do, including making records of your work, and then deleting the program and data from your computer completely.

The goal here is years later to be able to restore the program. By design with Electrum this should be possible using the password, seed words, notes as to the operating system and computer used, version of Electrum used, etc.

If you are uncertain about this, test it with a wallet with a nominal amount of funds.

Note that if you go this route don't enable 2FA. The chance you'll have the 2FA device such as your current phone five or ten years later is near zero.

Not good enough.

Passwords can easily be cracked and brute-forced. Also key-logger is an issue.

You need to COLD STORAGE your bitcoin if you want to be really safe.

I want to invest some more to Bitcoin for longer term. Till now I always used exchanges and blockchain.info to store small amounts. I am worried about running Electrum or any cold storage key generators, because of chance my Windows PC is infected. What are my options? I am thinking if it would be possible to run some Linux distribution with GUI from USB stick, install Electrum wallet on this OS to generate keys and seed words and backing everything up until needed.

It is possible, of course. It would be even better if you decided to use a separate laptop without Internet connection on which you could store your encrypted private keys and sign transactions. If you are not going to send your bitcoins often then you will be fine with simply generating your wallet with live CD operating system, encrypting it (doing it either in Electrum or using a third party app such as VeraCrypt) and store on multiple devices in case one fails.

It will be more safer if you do make use of electrum instead of exchange wallet and blockchain.info itself yet we have all known 3rd party wallets wont really give you the access into your wallet address and once those services shut down then your coins will be gone forever and theres no chance for recovery.

Regarding to your question, before making any transactions or transfers just make sure you do have a clean PC which arent prone to malware or any keyloggers. If you do make use electrum you can create and be sure to back it up the privatekeys and make your wallet encrypted anytime.

options:
- spend some money and buy a hardware wallet and store your funds there
- learn more about cold storage (https://en.bitcoin.it/wiki/Cold_storage) and choose one of the options that suits your need.

• if you want it to be your long term storage then use paper wallet. use something like bitaddress (http://bitaddress.org/), make a copy and run it offline on a clean computer and generate a key pair and print it on a paper, etch on a metal,...
  
• if you want a more dynamic wallet where you can still spend then use the Linux on a USB with Electrum on it. make sure you disable its network, encrypt the home folder (you need to install on USB not run live), disable guest login, encrypt Electrum wallet file, and make backups on paper from your seed and passwords.
• you can also always run a live linux from a DVD, generate a new wallet, write down the seed and turn it off. each time you want to use your wallet you will have to recover your wallet from seed, spend and turn off! it is not as safe but it is one way to do it.