Ways of Proving Casascius coin authenticity.

minerjones

legendary

Activity: 3206

Merit: 3596

Quote from: av8rjeff on February 10, 2019, 04:53:01 PM

I see. And so that could have the effect of devaluing the coin? Or is there some other purpose for the attack?

Yes, to some extent. Many collectors feel that a "X" face value coin should contain that exact amount.
Anything under or over would breach the collectible value plus you also now take into account a coin/amount that was not "maker funded"

And I have read that some of these attacks are used to reveal addresses/wallet info.
Something like this happened to Mycelium? or Samourai? wallets recently

jackbauercsgo

copper member

Activity: 507

Merit: 118

Dusting is a way to connect a wallet to a person.

Lauda

legendary

Activity: 2674

Merit: 2965

Terminated.

Quote from: minerjones on February 10, 2019, 05:06:50 PM

Quote from: av8rjeff on February 10, 2019, 04:53:01 PM

I see. And so that could have the effect of devaluing the coin? Or is there some other purpose for the attack?

Yes, to some extent. Many collectors feel that a "X" face value coin should contain that exact amount.
Anything under or over would breach the collectible value plus you also now take into account a coin/amount that was not "maker funded"

Collectors aren't known as the wisest people around here. One way to counter it would be to dust all known addresses that are still funded.

Quote from: av8rjeff on February 10, 2019, 04:53:01 PM

I see. And so that could have the effect of devaluing the coin? Or is there some other purpose for the attack?

The purpose of a dusting attack is not devaluing a coin; it's usually either promotion or a privacy attack on UTXO sets.

krogothmanhattan

legendary

Activity: 2520

Merit: 3238

The Stone the masons rejected was the cornerstone.

Quote from: av8rjeff on February 10, 2019, 04:53:01 PM

I see. And so that could have the effect of devaluing the coin? Or is there some other purpose for the attack?

If I buy a 1BTC loaded coin I want it at 1BTC not even one Satoshi over. In other words untainted.

av8rjeff

member

Activity: 356

Merit: 23

I see. And so that could have the effect of devaluing the coin? Or is there some other purpose for the attack?

anonymousminer

legendary

Activity: 1456

Merit: 1242

Quote from: av8rjeff on February 10, 2019, 01:21:25 PM

Um....what is "dusting"? Huh

Sending a small amount of BTC to the coins

av8rjeff

member

Activity: 356

Merit: 23

Um....what is "dusting"? Huh

krogothmanhattan

legendary

Activity: 2520

Merit: 3238

The Stone the masons rejected was the cornerstone.

Quote from: Hellot on January 30, 2019, 02:06:48 PM

Quote from: krogothmanhattan on January 30, 2019, 02:02:46 PM

Quote from: Hellot on January 30, 2019, 01:59:36 PM

Quote from: krogothmanhattan on January 30, 2019, 01:36:11 PM

Quote from: mojolama on January 30, 2019, 01:13:43 PM

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Post some photos here with the public key blurred if need be. We can take a look at the coin and hologram and let you know.

Also read this thread. https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

The printing for the public key is another authentication mechanism so blurring it will make authenticating it less certain. Things like ink pigment and bleeding under magnification should be consistent with your control(known good coins). The early coins that were inkjet printed right onto the hologram should also match. As time goes on these aspects of the coin will age and a newer copy would stand out.

That is true and good point. I was asking to blurr to prevent any dusting and also for him to keep pub key private and not be exposed.

I've yet to see a compelling argument that dusting is harmful. I have even sought out dusted coins for their historical significance like the Sochi Olympics duster. Not that I would but you can exclude the dust when you redeem it.

I like my Cas coins to be pure at 1btc Wink

But to each his own.

Hellot

hero member

Activity: 679

Merit: 526

Quote from: mojolama on January 30, 2019, 02:11:08 PM

Quote from: krogothmanhattan on January 30, 2019, 01:36:11 PM

Quote from: mojolama on January 30, 2019, 01:13:43 PM

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Post some photos here with the public key blurred if need be. We can take a look at the coin and hologram and let you know.

Also read this thread. https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

Thanks for offer. Thing is that I'm confident that they are original as got them directly from Mike . It is more to prove authenticity to a buyer and give them confidence when a deal is being done.

If you still have your correspondence from Mike that will help. It's not proof on its own but it adds to the certainty.

mojolama

member

Activity: 85

Merit: 11

Quote from: krogothmanhattan on January 30, 2019, 01:36:11 PM

Quote from: mojolama on January 30, 2019, 01:13:43 PM

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Post some photos here with the public key blurred if need be. We can take a look at the coin and hologram and let you know.

Also read this thread. https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

Thanks for offer. Thing is that I'm confident that they are original as got them directly from Mike . It is more to prove authenticity to a buyer and give them confidence when a deal is being done.

Hellot

hero member

Activity: 679

Merit: 526

Quote from: krogothmanhattan on January 30, 2019, 02:02:46 PM

Quote from: Hellot on January 30, 2019, 01:59:36 PM

Quote from: krogothmanhattan on January 30, 2019, 01:36:11 PM

Quote from: mojolama on January 30, 2019, 01:13:43 PM

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Post some photos here with the public key blurred if need be. We can take a look at the coin and hologram and let you know.

Also read this thread. https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

The printing for the public key is another authentication mechanism so blurring it will make authenticating it less certain. Things like ink pigment and bleeding under magnification should be consistent with your control(known good coins). The early coins that were inkjet printed right onto the hologram should also match. As time goes on these aspects of the coin will age and a newer copy would stand out.

That is true and good point. I was asking to blurr to prevent any dusting and also for him to keep pub key private and not be exposed.

I've yet to see a compelling argument that dusting is harmful. I have even sought out dusted coins for their historical significance like the Sochi Olympics duster. Not that I would but you can exclude the dust when you redeem it.

krogothmanhattan

legendary

Activity: 2520

Merit: 3238

The Stone the masons rejected was the cornerstone.

Quote from: OgNasty on January 30, 2019, 02:01:49 PM

Quote from: mojolama on January 30, 2019, 01:13:43 PM

Suggestions for other methods to authenticate?

Take a look at some images of fakes and familiarize yourself with the differences.

This thread is an excellent source to compare some pretty good fakes against the real Casascius https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

krogothmanhattan

legendary

Activity: 2520

Merit: 3238

The Stone the masons rejected was the cornerstone.

Quote from: Hellot on January 30, 2019, 01:59:36 PM

Quote from: krogothmanhattan on January 30, 2019, 01:36:11 PM

Quote from: mojolama on January 30, 2019, 01:13:43 PM

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Post some photos here with the public key blurred if need be. We can take a look at the coin and hologram and let you know.

Also read this thread. https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

The printing for the public key is another authentication mechanism so blurring it will make authenticating it less certain. Things like ink pigment and bleeding under magnification should be consistent with your control(known good coins). The early coins that were inkjet printed right onto the hologram should also match. As time goes on these aspects of the coin will age and a newer copy would stand out.

That is true and good point.

I was suggesting to blurr the public keys in order to prevent any dusting and also for him to keep public keys private and not be exposed.

OgNasty

donator

Activity: 4760

Merit: 4323

Leading Crypto Sports Betting & Casino Platform

Quote from: mojolama on January 30, 2019, 01:13:43 PM

Suggestions for other methods to authenticate?

Take a look at some images of fakes and familiarize yourself with the differences.

dazedfool

legendary

Activity: 1534

Merit: 1133

derp

Just mail them all to me for authentication. I'll be sure to properly dispose of any fakes Wink

Hellot

hero member

Activity: 679

Merit: 526

Quote from: krogothmanhattan on January 30, 2019, 01:36:11 PM

Quote from: mojolama on January 30, 2019, 01:13:43 PM

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Post some photos here with the public key blurred if need be. We can take a look at the coin and hologram and let you know.

Also read this thread. https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

The printing for the public key is another authentication mechanism so blurring it will make authenticating it less certain. Things like ink pigment and bleeding under magnification should be consistent with your control(known good coins). The early coins that were inkjet printed right onto the hologram should also match. As time goes on these aspects of the coin will age and a newer copy would stand out.

vizique

legendary

Activity: 2433

Merit: 1642

This might be useful to you

https://casascius.uberbills.com/

Viz

krogothmanhattan

legendary

Activity: 2520

Merit: 3238

The Stone the masons rejected was the cornerstone.

Quote from: mojolama on January 30, 2019, 01:13:43 PM

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Post some photos here with the public key blurred if need be. We can take a look at the coin and hologram and let you know.

Also read this thread. https://bitcointalksearch.org/topic/beware-of-fake-casascius-coins-3257048

mdayonliner

copper member

Activity: 630

Merit: 420

We are Bitcoin!

Quote from: mojolama on January 30, 2019, 01:13:43 PM

Suggestions for other methods to authenticate?

I will be following this topic hoping to get some good insights. I always thought to play with coins and collectibles but I have zero Idea how to find the authenticity and also security.

- How do you know in a Casascius coin the private key is not compromised? I hope I did not ask a stupid question Tongue

OP: Thanks for creating the topic.

mojolama

member

Activity: 85

Merit: 11

As an early Casascius buyer/holder I viewed these coins as nice memorabilia items and didn’t think of getting Chain of custody for future authentication.
Obviously with the high value these coins have now it's becoming something both seller and buyer want assurance on.
So if a seller doesn’t have chain of custody would the next best solution be to have the coins in question checked by trusted experts? Eg: Hologram, coin pressing, ink used etc.

Suggestions for other methods to authenticate?

Topic: Ways of Proving Casascius coin authenticity. (Read 398 times)