2013-03-18 Wired: Ring of Bitcoins: Why Your Digital Wallet Belongs ...

[Zomdifros]

http://www.wired.com/wiredenterprise/2013/03/bitcoin-ring/

Then Shrem asked his father, a jeweler, engrave the private key on a ring. Yes, a physical ring he could slip onto his finger. “I took the key, and I literally called my father and said it to him over the phone,” Shrem remembers. “He wrote it down on a piece of paper. In his factory here in New York City, he has a jewelry engraver. He took a piece of silver, and he engraved it into a ring.”

This looks pretty cool, having your hardware wallet on your finger!

Well, he engraved most of it into the ring. To add a little extra security, Shrem had his father leave out one of the digits from the private key. That’s stored in Shrem’s head — and only his head.

Thinking of it, this would be perfect for wedding rings, were bots newlyweds engrave only half of the private key in their ring. Wedding gifts could then be donated to the corresponding public address

[Mike Hearn]

Great idea, great PR. However skipping just one digit from the ring won't stop people brute forcing the key if the ring is stolen. Maybe it wasn't a great idea for Charlie to identify himself like that, it seems a big part of the benefit of that trick is the obscurity.

[Peter Todd]

Great idea, great PR. However skipping just one digit from the ring won't stop people brute forcing the key if the ring is stolen. Maybe it wasn't a great idea for Charlie to identify himself like that, it seems a big part of the benefit of that trick is the obscurity.

Well, for all we know he's lying about what the trick actually was. 

[DublinBrian]

Charlie should keep the whereabouts of his private key, more private. Not knowing which digit is missing, wont stop a thief cutting off his finger to try to brute force the possibilities.

It has happened in other circumstances

Police in Malaysia are hunting for members of a violent gang who chopped off a car owner's finger to get round the vehicle's hi-tech security system.

http://news.bbc.co.uk/2/hi/asia-pacific/4396831.stm

[Stephen Gornick]

Well, for all we know he's lying about what the trick actually was. 

And if the ring is stolen the funds could be transferred (assuming he has a backup copy of the key) before any cracking attempt could solve it.

But yes, he might have said "there's only a few bitcoins, the metal is worth more than the bitcoins" or something like that so as to not incent those who might consider the possibilities.

[molecular]

hey charlie, let's go have a drink or two. I'll pay for blow and hookers...

seriously though... just use a brainwallet for this kind of stuff, then pretend the key is on the ring. Brain is more valuable than finger.

it's all PR I guess... good PR.

[nimda]

Well, he engraved most of it into the ring. To add a little extra security, Shrem had his father leave out one of the digits from the private key. That’s stored in Shrem’s head — and only his head.

base58 wallet format is 52 characters long. One of those is the preceding 5. Drop one of them from somewhere in the string. Now you have 52 possible locations to add one of 58 digits. I'm afraid 3016 possible private keys is a tiny number, and could be brute-forced inside of a second.

Good luck with that.

[FreddyFender]

That's the day we started calling him 'three-finger Charlie'.

[Mike Christ]

The engraving isn't obvious, so as long as he doesn't tell the world he has money on his finger, he'll be safe.  Most of us carry wallets (and less than 10% of us carry purses!), but we're all okay--well, sometimes we're all okay.

[jgarzik]

The engraving isn't obvious, so as long as he doesn't tell the world he has money on his finger, he'll be safe.

Doh!