Inside PaperSafe – Bitcoin’s Answer to the Dollar Bill

A great many people choose to store their Bitcoins offline, often in a physical object. There are countless variations on this concept: ranging from physical coins, to cards, to small devices dedicated to Bitcoin storage. PaperSafe serves to add another physical representation of Bitcoins to the roster: certificates, inspired by old stocks.

Originally started as a passion project, PaperSafe is the brainchild of BitcoinTalk user BG4. After over a year of development, they are now being auctioned off to the public on the Bitcointalk forums, with the first edition selling for a total of 0.3 BTC on Saturday.

Inside the PaperSafe

We interviewed BG4 on the inspiration and manufacturing process behind PaperSafe. Here’s what he had to say.

What inspired you to create PaperSafe?

PaperSafe Bitcoin wallets started out as an art project and still are. I guess I have always liked the looks of old stock certificate art, and mining stocks from the early 1900s. The block prints and engravings are incredible, and I have a small collection that I used for inspiration. I see my certificates as a deed to a small part of the Blockchain that someone can own and store Bitcoin on for long term cold storage.
At the time, I really did not like the standard paper wallets that were printed from web sites, although sites like and have been a major inspiration. I just wanted a paper wallet for my own personal use, that looked like nothing seen before. It was a work in progress that took over a year to complete…

Security is a primary concern when it comes to physical wallets. What measures do you take with Papersafe to ensure security?

One of the biggest security measures is the key generation. I have an old offline laptop with a clean OS and the programs from and installed. I have been using it for some time now. The next part is covering the password as soon as the encrypted keys are printed. The scratch off and hologram are placed by hand within a lightly printed box to ensure everything is straight, and small wire picks are used to place them. Its the most nervous part of the process. All the other parts of the security is anti copy/forgery and tamper. It’s all in the paper, graphics, embossers, stamps, and UV ink artwork which is all done by hand.

I wanted as many different types of security implemented as possible. I think the biggest concern people will have is “do I keep the private keys?”. All I have to say to that is that I put way too much time and thought into PaperSafe. I never see the unencrypted private key. I produce PaperSafe Bitcoin wallets as I would for myself: as secure as possible. Long term stability of the paper, hologram and scratch off concealment is my biggest concern. That is unknown at this point in the project.

Could you give us an overview of the manufacturing process?

The process all starts with the paper. I tried over a dozen different types of security paper before I found one that I liked. I use a level 2 secure rub paper. It will print the words “VOID UNAUTHORIZED COPY” if it is copied or scanned, to prevent forgery. The paper has micro printing. When you rub your finger across it, it will disappear. Also, micro threads are embedded in the paper that glow under black light.

The paper is first printed with a random password. The main graphics are then printed. The keys are encrypted with the pre printed password and printed for the third printing. Once the certificate comes out of the printer, the scratch off cover is applied over the password, then covered over with a clear hologram. The forth and final print is a tamper evident graphic over the whole password area. This graphic is ment to tell if the hologram has been disturbed.

At this point in the process, the printing is done. The certificates are then embossed with 2 different seals: one is a Bitcoin logo and the second one is what looks like a corporate seal found on stock certificates. I use 2 different numbering machines: one stamps consecutive numbers in black ink, the other is with UV invisible ink. A small hologram is placed over one of the UV numbers.

The last step is the fun part. I turn the lights off in the room and work under the light from a black light to embellish the graphics with invisible UV ink markers. I can see the marker tip and can add the finest detail with a steady hand. As the ink drys, the color gets bright and glows. The PaperSafe is now complete.

The PaperSafe paper wallet project was finished in November of last year. I printed the certificates that I set out to make, and then packed up the supplies for the last 5 months. I didn’t think anyone would be interested in pre-printed paper wallets until I introduced the project on I have received many compliments from the people there for that artwork that I put into the paper wallets, but they still were concerned about the key security. So I decided to produce 10 Artist Proof Certificates and auction them first on the Bitcointalk forum. After this, only 100 Satoshi Note “genesis Block” certificates will be sold on the project’s website: I have plans for more designs. The next design I want to release is my version of the old mining stocks with a Bitcoin twist. The Blockchain Mining Stock certificate is one of a handful of designs I did in November. along with different denomination certificates and a satoshi note that is numbered with the blockchain.

A recent decision to add to the security of the certificates is to incorporate a Near Field Communication tag. The NFC tag has a unique ID programmed at the factory and can be programmed to store different data like Read-Only URLs of Public Key addresses, Ascii Text of private keys etc. The tags can even be used with the Smart phone app. I think this addition will make Papersafe wallets usable with other projects. Also, a “Print your own Keys” versions o PaperSafe wallets are on the drawing board..

In the end, I hope I can keep building on this concept of a transferable, collectable paper wallet that people can pass like paper currency, or use for long term bitcoin storage. If you are against this practice, then the PaperSafe Wallet is just a Bitcoin wallet Art project; nothing else.

BG4, speaking directly to CoinBuzz.