Quote from: Nestade on June 20, 2018, 07:31:13 AM

Hi,

In this guide I'd like to show you how to do offline-transactions using MyEtherWallet.
By using this method your private-key won't won't leave the offline machine so this is the safest way of sending transactions without a hardware-wallet.

First of all something about your private-key/keystore-file/recovery-seed: Do NOT store this files on your computer which is connected to the internet! If you're getting infected my malware you may lose all of your coins/tokens linked to this private-key. The safest way would be just using your keystore-file on your offline computer to sign transactions and storing your private-key/recovery seed safely on paper. Your private-key and recovery-seed are unencrypted provide instant access to your wallet while the keystore-file is encrypted and requires an additional password.

Requirements:
- a computer which is connected to the internet
- a computer which isn't connected to the internet
- Your ETH public-key
- Your ETH private-key (Keystorefile should be preferred)

Installing MyEtherWallet locally [Do this on the offline computer]

Download the local version of MyEtherWallet from the official MyEtherWallet Github (etherwallet-vX.X.X.X.zip):
https://github.com/kvhnuke/etherwallet/releases

Move "etherwallet-vX.X.X.X.zip" to your offline computer (USB Stick, Smartphone, ...) and extract the content from the ZIP.

Open MyEtherWallet by double clicking 'index.html' - you may have to right-click it, then go to 'Open with' and select a browser; I'd recommend using Google Chrome - you may want to download it on your online machine and transfer it to the offline machine.

Making an offline transaction

STEP 1: [ONLINE] Go to the MyEtherWallet-Website and select the 'Send Offline'-tab (https://www.myetherwallet.com/#offline-transaction). If needed adjust your GWEI according to https://ethgasstation.info/ by clicking on 'Gas Price: X GWEI' in the upper right corner and adjusting the slider to your needs. Then enter the public-address of the sender account into the 'From Address' textbox and click 'Generate'.
Write down the contents of 'Gas Price' and 'Nonce'.

STEP 2: [OFFLINE] Open your local copy of MyEtherWallet, select the 'Send Offline'-tab and scroll down to 'Step 2: Generate Transaction (Offline Computer)'.

Enter the following information:
- To Address: Receiver-address
- Value / Amount to Send: Amount you want to send (it's also possible to send Tokens by clicking on 'ETH' on the right side of the textbox and selecting the respective Token in the dropdown-menu)
- Gas Limit: https://kb.myetherwallet.com/gas/what-is-gas-ethereum.html
- Gas Price: Value from STEP 1
- Nonce: Value from STEP 1
- Data: optional - leave empty if not needed

Now scroll down until you see 'How would you like to access your wallet?' and log in using your preferred authentication-method (I'd recommend using your Keystore-File!) and click 'Unlock'.

Click 'Generate Transaction'

STEP 3: [OFFLINE] You'll now see two textboxes - 'Raw Transaction' and 'Signed Transaction'. Copy the content from 'Signed Transaction' and transfer it to your online computer.

STEP 4: [ONLINE] Go back to the MyEtherWallet-Website and select the 'Send Offline'-tab (https://www.myetherwallet.com/#offline-transaction). Scroll down to 'Step 3: Send / Publish Transaction (Online Computer)', enter your signed transaction, click 'Send Transaction' and confirm it.

Congratulations, you're done

Sidenote: To check your balance just use https://ethplorer.io/ or https://etherscan.io/ or log in to MyEtherWallet just using your public-key (View only of couse).

If you have any questions please feel free to ask anytime.

Best regards,
Nestade

This is gonna be good but it's too complicated to update our wallet.
I'm okay with using MEW via google chrome MEW extension, it's very good and easy to use.
Every time you want to login, you just have to enter the password and you can view or send ETH from there.