Virtual Autograph Using Bitcoin

I started this blog in January 2003. One of my first posts ever, published on 7 January 2003, had this to say under the title “Virtual Autograph”:

Anyone can buy PGP 8.0 Personal Edition from Phil Zimmermann, the original author.

I don’t know if there is a market for the idea, but instead of selling exactly the same file PGP Corp is selling, he might add his autograph to some metadata associated with the file, signing a short text of the buyers choosing with his private key, and adding a serial number. Sort of a personal version. Maybe personal versions with a one-digit serial number would have some rarity value on Ebay.

At the time, the Bitcoin network was not yet around.

Now, with the functionality available with Bitcoin, I have developed this idea somewhat further.

Let me explain this with my second global warming science fiction novel “Tasneem” as a test case.

What I have done, I have paid 100 millibitcoin (around $12 at present prices) from my main address at

1KfLenzmpCEjNhdNs2Y6txuaJAFLUNzfjZ to the address 1KfL1PSScrJ8HJovfLeoChZABV37Km2CW that I use only for this autograph. Note that the second address begins with “KfL1”. The first three digits designate my name, and the fourth one is the number one, since this is the first digital Bitcoin autograph ever.

In the public note included in the Blockchain I wrote “first autograph ever”.

Then I added information to this effect to a special autographed version PDF file, which is now available at the blog post for “Tasneem” (right at the very end).

What this means, everyone can download this autographed version. But only the holder of the private key for the address 1KfL1PSScrJ8HJovfLeoChZABV37Km2CW can claim to be the owner of the autograph.

At the moment of this writing, I am holding the private key myself. That’s because there is no one who would want my autograph right now anyway.

Note that the autograph always has the value of the 100 Millibitcoin I used to produce it in the first place. Again, that’s about $12 right now. That’s an interesting difference to traditional autographs.

 Setting this up this way also means that the holder of the autograph can transfer this autograph to one (and only one) new holder. In Bitcoin network terms, the fact that the Bitcoin network solves the double spending problem means that this problem is also solved for the secondary market in autographs.

I hear that patents were requested for the simple idea of incorporating a simple picture of a signature into electronic books. The people at claim to have developed this idea.

In contrast I claim that I had that idea 10 years before, as is easily proven with my blog post referenced above. That should be prior art enough to blow any patent protection for this kind of simple scheme away.

The main purpose of this post is to disclose my new idea of using Bitcoin as a method to solve the double spending problem for autographs. I would hate to see someone filing another patent for this, since it is fairly obvious for anyone familiar with the Bitcoin network, and it seems to be the obvious way to go for autographing e-books.

Published by kflenz

Professor at Aoyama Gakuin University, Tokyo. Author of Lenz Blog (since 2003,

One thought on “Virtual Autograph Using Bitcoin

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