Bitcoin Forum

I recently purchases this microscope (http://www.amazon.com/Celestron-Deluxe-Handheld-Digital-Microscope/dp/B004QF0A1Y/) from amazon, and started looking at everything I can get my hands on at 40-150x.  One such thing was the hologram on the back of a casascius physical Bitcoin.

I believe this is actually only 10x and 40x, but 40x was enough to see what I didn't know was even there:  four rings of "CASASCIUS" just inside where it says "ORIGINAL" on the coin.  Looking at it by eye, I can barely identify the bigger outer ring, and definitely can't identify the smaller three inner rings.  This is impressive:  casascius really put a lot of quality into these holographic films!

http://dl.dropbox.com/u/1139081/BitcoinImg/casascius_40x.jpg
http://dl.dropbox.com/u/1139081/BitcoinImg/casascius_150x.jpg
http://dl.dropbox.com/u/1139081/BitcoinImg/micro_vires_in_numeris.png

Really does look awesome.

I might actually order one after all.

That looks like a dot-matrix process. I was wondering about that.

I wonder how long until someone tries an xray microscope (or whatever they are called) to see the private key underneath.

wow i really like the microscopic details

If only I could have not had the first one come out "CASACIUS" (misspelled) in the largest fine print (partly visible in one of the photos above - first photo, 11 o'clock position).

We actually did two designs and I picked through design number 1 with a fine tooth comb for detail, then went with design number 2 without having done the same. I noticed it instantly once I took some light to the then-newly finished holograms.  Series 2 fixes that.

Looking forward to it.

You mean they can't?  :)

nice pics @etotheipi

Cool, now someone needs to buy an electron microscope and do this  8)

Right, maybe if MNW wins his 10K BTC bet...

http://benkrasnow.blogspot.com/2011/03/diy-scanning-electron-microscope.html

awesome shot, etotheipi, thanks for sharing.

"I always wanted to know how this bitcoin thing works in detail" ;)

I'm a radiology resident and back when BitBills came out, I took a low kV radiograph of it to see if I could bring out any detail...I was hoping the ink was made from the oxide of some metal...no luck. The BitBill was glorified laminated paper, which would be much more susceptible to xray hacking than a metal coin. I strongly doubt anyone will find success with a Casascius coin.

How are you supposed to pronounce Casascius?

I've heard different people use different pronunciations.

There is an old youtube video of someone called Plato buying gas from Casascius. He pronounces it Cuh Say Shee Us.

http://www.youtube.com/watch?v=H9jC0TP-Yug

In my head, I always pronounced it "Ka say sh us". Three syllables, "sh us" is one syllable.

Anyway, the detail on those are awesome. I might order some. But they are MtGox codes right?

This is the one I use and consider correct, but I consider pretty much all reasonable variations correct as well, including any of the following:

* Ka Say Shus
* Ka Sassy Us

Common, but less correct being inconsistent with the spelling
* Cass See Us
* Cass a Cuss

They are not MtGox codes - they are private keys - MiniKeys to be specific.  MtGox can redeem them, but so can many other places (easiest way is to import into a throwaway Blockchain.info wallet and send the coins to your desired destination)

Very nice. I'll be buying some in the near future as a sort of long term investment. I assume these keys will still work in 10-20 years when Bitcoins are potentially worth thousands of dollars?

You'd want to redeem the value and put them in cold storage if your plan is long term investment. Or just buy bitcoins from an exchange and send them to offline addresses.

Hi mufa23,

keys will be ok, but what about the little piece of paper on which they're written? And what about ink?

Will these keys be readable in 5 years? And in 10 or 20 years?

spiccioli

I have seen photos lose their color fidelity over the years, but have you ever seen old documents turn into blank paper? Me neither. :)

casascius,

I have some of your coins and I was really wondering how long I can expect to be able to read them.

I was not trying to scare anyone.

Do you print them or do you write them by hand? What kind of ink do you use?

spiccioli

They are inkjet-printed, and I processed the private keys entirely myself.  Inkjet was deliberately chosen over several potential other possibilities including laser printing, thermal printing, dye sublimation, and laser engraving (all of which are available to me), with security and longevity being primary concerns.

The inkjet used to print the private keys is different from the inkjet on the outside of the series 1 coins.

If somehow the inkjet began to fade over time, we'd start to discover this as people opened their coins for redemption, long before the blacks would fade to white (assuming such was possible).

As for whether I'd write them by hand, no way - that would be egregious both in terms of difficulty and possibility for transcription mistakes.  However, I did inspect every single sheet of keys (330/sheet) by hand to ensure complete and legible printing, proper alignment, proper front-to-back registration and key correlation (public/private), as well as completeness of the print job without any duplications.  They are then laser-cut into circles.  So I am totally confident that every single key circle is good, and have no shivers about sending (for example) 1000 BTC to one of them when one goes in a gold coin.

casascius,

thanks for the explanation!

spiccioli

+1

As a graduate student with access to high resolution microscopes and an SEM I am tempted to buy one of these just to examine it.

DO IT

If you examine one and post your findings I will reimburse the cost of one coin plus shipping.

Do you have a coin denomination in particular you'd like examined? Otherwise I will just look at the gen2 1 btc coin

I read about these physical bitcoins only now - I think it is a nice concept to make bitcoin a bit more tangible and spread it further, and of course it could be used in offline transactions for small amounts.

Two question to Mike, both not crucially important, I am just asking for curiosity:

First, the Casascius 10 BTC Silver Round (http://casascius.appspot.com/group?type=5) has 3 circles of seemingly random 0s and 1s around it (visible even w/o microscope ;-) ). Is it really random, or does this sequence of bits carry any hidden message/meaning (byte code, morse code or whatever)? It would surprise me if these carefully and well-designed coins did not carry any meaning in this bit sequence...

Secondly, what does the nickname "casascius" stand for? At least it is not easy to remember, I always have to concentrate to avoid mistyping it.

Nice images. Not bad for the money.

It's ASCII for "Bitcoin: an idea too big to fail". The BTC25 coin has a similar message that reads "You asked for change, we gave you coins".

given the recent renewed interest in casascius coins, i thought this thread deserved a bump... yw.