Voucher & Paper Wallet Generator

Projects
#21

Hi! I found the current sources and pushed them to github. I also added two new paper wallet designs, the two old ones looked boring.

demo_nem1
demo_nem1.jpg1200×480 67.5 KB

demo_nem2
demo_nem2.jpg1200×480 81.7 KB

Link to the new executable: https://github.com/owon/voucher-paper_wallet/blob/master/voucher-ppwlt06%20--%20Apostille%20TX%20e758682b002abd85713c5dc4a5f06f4470cccdd4fc81eda167989e968fbbb464%20--%20Date%202018-05-05.zip

As usual: Always take care of your private keys and verify the publisher with NEM Apostille!

Have fun!

Cheers
Owon

7 Likes
Create cold wallet with universal client
#22

Thanks a lot!!

I like the new designs

#23

Good morning dear friend.
What does it mean in your: paperwallet &voucher generator
This is your new Nem address
To unlock this wallet, please install the Android/iOS NEM Wallet and scan the QR printed on this voucher ?

Does it mean that it is blocked and the blockchain is not yet?

The same goes for other portfolio generators such as bitaddres.org https://bitcoinwalletpaper.com/en/ https://bitcoinwalletpaper.com/litecoin/ etc …?

Do the portfolios of all the portfolio generators expire?

You could say that these generated portfolios are not yet in the Blockchain?

Or because they are generated under the parameters of the Blockchain are they enabled to receive funds and can they operate forever?

My question is for that text that is in your

Voucher & Paper Wallet and also because a programmer with 40 years of experience told me that the Wallets like these and others generated by other generators of multiple portfolios like these break Blockchain protocols and still do not belong to the Blockchain.

That only those registered with emails and under the parameters such as those used by the EXCHANGES and as those generated by each user are those valid in the blockchain?

#24

Hi Fredy,

I don’t know how other paper wallet generators on other blockchains work, but I can explain how my tool is working.

Blockchains use public / private key cryptography to secure funds and sign transactions. And this is exactly how my generator works as well. When you create a new paper wallet, the generator first creates a private key and then the public address/receiving address for that particular private key.
This is what you see on my paper wallets. The address on the left is your public address, used to receive funds. The one in the middle is your private key.

If someone sends funds to the address shown on the left, the transaction will be stored on the blockchain. You can always check the balance of an address with a block explorer. Everything is on chain.

To spend the funds, you need the private key. As soon as you import the private key to a wallet, you are able to sign transactions for the corresponding address and you can spend the funds.
This is how my paper wallet generator works.
“…to unlock this wallet, please install the Android…” --> This is just the easiest way to import the private key into a wallet, you can just scan the QR code. But you can also use any other NEM wallet and import the RAW private key. RAW private key and mobile import format private key are the same, just represented in a different way - and the mobile import format key contains some more information as well. But both are the same, just written in a different format.

Paper wallets from my generator have no expiry date. At least as long as NEM does not change the address creation algorithm. (this is highly unlikely)

Imo paper wallets are the safest way to store funds - IF you do it right:

  1. Keep your private key safe!!! A person having access to your private key can spend the funds!
    Your keys - your money - it’s that simple.
  2. Only use paper wallet generators you trust, or better: Check the source code!
  3. Never use a generator that is not open source
  4. Never use a generator that creates lazy private keys (it is very important to have a secure random key)
  5. Never use online generators on the internet! Only use offline generators running on YOUR computer while the computer is disconnected from the network!

I hope I was able to clarify some things for you.

Have a good day!

2 Likes
#25

Good day. Friend.
Could you tell me if the Wallets can be produced without the image in the background?
Let alone the alphanumeric keys to save disk space?

#26

Hello Fredy,

yes, it should be possible to use your own (blank or other solid color) images, unfortunately it’s not possible in the normal GUI yet. You would have to modify the sources. As an IDE, you may use Visual Studio in the community edition (for Windows- free) or MonoDevelop (Linux). Your (blank) image must be 1200x480 px in size. You can replace one of the existing pictures, that are currently added as a resource to the project, with yours. Then recompile and run the project.

Regarding the keys: You may want to include at least the RAW private key to be able to recover funds. You may un-tick the “Include mobile wallet import format”, this is somehow optional. However, it is the easiest way to import the paper wallet into the client.

I don’t know about your actual plans. The storage requirement is about ~70KB-80KB per paper wallet. You may save some bytes with a solid/blank background.

If storage is still an issue, you may consider to create and store public/private key pairs instead of paper wallet images.

And please make sure to select a safe storage for the private keys, this is ESSENTIAL!