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Topic: A microscopic view of Casacius physical bitcoins (Read 5514 times)

sr. member
Activity: 254
Merit: 250
February 21, 2013, 08:45:40 PM
#33
given the recent renewed interest in casascius coins, i thought this thread deserved a bump... yw.
legendary
Activity: 4326
Merit: 3041
Vile Vixen and Miss Bitcointalk 2021-2023
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...
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".
member
Activity: 70
Merit: 10
Nice images. Not bad for the money.
sr. member
Activity: 278
Merit: 250
Bitcoin-Note-and-Voucher-Printing-Empowerer
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.
member
Activity: 112
Merit: 10
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.

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
vip
Activity: 1386
Merit: 1136
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
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.

If you examine one and post your findings I will reimburse the cost of one coin plus shipping.
sr. member
Activity: 280
Merit: 250
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
member
Activity: 112
Merit: 10
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.
sr. member
Activity: 280
Merit: 250
+1
legendary
Activity: 1378
Merit: 1003
nec sine labore
Do you print them or do you write them by hand? What kind of ink do you use?

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
vip
Activity: 1386
Merit: 1136
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
Do you print them or do you write them by hand? What kind of ink do you use?

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.
legendary
Activity: 1378
Merit: 1003
nec sine labore
I have seen photos lose their color fidelity over the years, but have you ever seen old documents turn into blank paper? Me neither. Smiley

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
vip
Activity: 1386
Merit: 1136
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
I have seen photos lose their color fidelity over the years, but have you ever seen old documents turn into blank paper? Me neither. Smiley
legendary
Activity: 1378
Merit: 1003
nec sine labore
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?

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
legendary
Activity: 3416
Merit: 1912
The Concierge of Crypto
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.
legendary
Activity: 1022
Merit: 1001
I'd fight Gandhi.
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?
vip
Activity: 1386
Merit: 1136
The Casascius 1oz 10BTC Silver Round (w/ Gold B)
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)
legendary
Activity: 1022
Merit: 1001
I'd fight Gandhi.
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?
sr. member
Activity: 254
Merit: 250
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
sr. member
Activity: 434
Merit: 250
100%
How are you supposed to pronounce Casascius?

I've heard different people use different pronunciations.

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