[Ethereum] Sweeping ETH from a 2 year old paper wallet, help

Will the wallets created at this moment in time be backwards compatible in the future? (Metropolis, Serenity, ...)

I can confirm that MyEtherWallet will always provide backwards capabilities with older version of our encrypted versions, as well as common methods created by other wallets. We are currently in the process of switching to use the same encryption as geth which will (1) help standardize across wallets and (2) make it easier for people to move from MyEtherWallet -> Mist in the future. We also hope to implement other methods of accessing (ie: Jaxx mnemonics, etc.).

For reference, the only things that might change as Ethereum "grows up" is the json / keystore / encryption / etc. formats of the private key. In the end, it's still decrypting to get to the same version of the private key. The way you store it and decrypt it just might change. Most, if not all, wallet providers are going to stay up to date as encryption methods and standards emerge and provide backwards capabilities and cross-capabilities.

How do I verify if the wallets have been created correctly (private key), without first sending a small amount in and out of the wallet?

Personally, I use the MyEtherWallet offline transaction tab to test in and out of any new deep-cold-storage wallet. I suppose you could import the key using a different client and verify it gives you the same address. So, since you are using MyEtherWallet which using Javascript, you could import the unencrypted private key into geth and verify the address, or into eth, or whatever. You will not want to cross-verify with another Javascript implementation (like EthAddress).

Is there anything else I have to consider and I am correct with my assumptions?

I recommend keeping a copy of EthAddress or MyEtherWallet's zipped repo with your cold-storage keys. That way in the future if something changes or something, you'll still have a local version, one that you know works with your private key, to run.

Why are there only third-party web wallet creation pages on the internet and no official ones (yet)? (Maybe because of: Ethereum: "We are making tools for tool-makers“?)

The Ethereum developers have stated that they are working towards a light client. At this point, I find it impressive that they have so many clients in different languages and the Mist / Ethereum Wallet is already as strong as it is. It's been 7 months since launch. Also, keep in mind that the Ethereum Wallet / Mist is so much more than a wallet. A lot of people seem to forget this because that's all they use it for. But in reality, the things they are doing with contracts and tokens are amazing and is what they are focused on at this point.

For reference, here are the three sites mentioned in this thread:

• MyEtherWallet repo

• Icebox by christianlundkvist @ ConsenSys

• EthAddress.org by ryepdx

full disclosure: I am co-founder of MyEtherWallet. I try to be objective.

There are a few different reasons for verifying your key.

1. To make sure you actually saved the private key and address correctly. e.g. You saved a private key but recorded the address 0x122... instead of 0x123... (note: you should avoid hand writing things anyways).

2. To make sure you have all the necessary information, including the password. e.g. You thought you typed password but you actually typed passwordd. e.g. You saved the public key and password but not the private key. e.g. You saved the keystore file but then opened it in Microsoft Word and now it's corrupted.

3. To make sure the software you used derived the correct private / public key pair.

For the first two items:

You can simply ensure you can access the wallet via the private key or keystore file and (1) make sure it unlocks (2) make sure the address matches what you have recorded. On MyEtherWallet, you can use any of the other tabs to do so: View Wallet Info, Send Transaction, Digix, or DAO. If you are able to access the wallet without errors and the address is the same, you're golden.

The third item is a bit trickier. You can either:

1. Use a different library to access the wallet and make sure the public / private pair is the same as what you have recorded. By library, I mean a different programming language / client. So, with MyEtherWallet you would want to verify with a non-Javascript library, like geth (Go) or parity (Rust) or c++ (eth). These can be a bit tricky to install in a cold storage environment so...

2. Send a small amount of ETH to your new wallet. Then send that small amount back out using the Offline Transaction tab. If your transaction successfully arrives and leaves your wallet you can ensure you have a private key that accesses the address you saved, and you can both successfully send and receive ETH at that address.

Remember:

• When making backups and verifying backups, always verify what you saved via where ever you saved it and, ideally, wherever it is going to be stored. It does you no good to copy the address from MyEtherWallet -> Text Document -> MyEtherWallet again. Instead copy all info to a document / folder. Then copy/select it from that location and attempt to access via MyEtherWallet.

• Always make multiple backups. Please. Saving it on your hard drive does nothing if your HDD crashes. Saving it on a single piece of paper does nothing if your house burns down. Etc.

• Take your time. Practice if this is a new experience for you. Do the entire process and then do it again until you are comfortable and confident. You can make as many wallets as you want, just make sure you don't get them confused!