<oembed><type>rich</type><version>1.0</version><author_name>npub1kf0ppcjaguxekg24yx6smgxlu73qn0k8lm0t2wrqc0scpl7u3sgsmf3f58</author_name><author_url>https://nostr.ae/npub1kf0ppcjaguxekg24yx6smgxlu73qn0k8lm0t2wrqc0scpl7u3sgsmf3f58</author_url><provider_name>njump</provider_name><provider_url>https://nostr.ae</provider_url><html>📅 Original date posted:2015-06-21&#xA;📝 Original message:On Sun, Jun 21, 2015 at 12:42 AM, Eric Lombrozo &lt;elombrozo at gmail.com&gt; wrote:&#xA;&#xA;&gt; Thanks for asking *the* question, Jeff. We often get caught up in these&#xA;&gt; philosophical debates…but at the end of the day we need something concrete.&#xA;&gt;&#xA;&gt; Even more important than the specific software you’re using is the&#xA;&gt; security policy.&#xA;&gt;&#xA;&gt; If you must accept zero confirmation transactions, there are a few&#xA;&gt; concrete things you can do to reduce your exposure:&#xA;&gt;&#xA;&gt; 1) limit the transaction amounts for zero confirmation transactions - do&#xA;&gt; not accept them for very high priced goods…especially if they require&#xA;&gt; physical shipping.&#xA;&gt; 2) limit the total amount of unconfirmed revenue you’ll tolerate at any&#xA;&gt; given moment - if the amount is exceeded, require confirmations.&#xA;&gt; 3) give merchants of subscription services (i.e. servers, hosting, etc…)&#xA;&gt; the ability to shut the user out if a double-spend is detected.&#xA;&gt;&#xA;&#xA;Already done -- BitPay merchants choose their level of transaction&#xA;security.  Level of confirmations is directly exposed to merchants, so that&#xA;they choose the level of risk for themselves.&#xA;&#xA;Physically shipped orders and subscriptions are actually the easy cases and&#xA;are already handled.  These can accept 0-conf for an initial order phase,&#xA;then have the luxury of time to wait for confirmations before shipping /&#xA;canceling a subscription.&#xA;&#xA;Electronic goods instantly delivered are the toughest use case.  Even&#xA;there, merchants choose their level of risk.&#xA;&#xA;&#xA;&#xA;&gt; 4) collect legal information on purchasers (or have the merchants collect&#xA;&gt; this information) so you have someone to go after if they try to screw you&#xA;&gt;&#xA;&#xA;The system requests this information on orders yes.  Merchants also collect&#xA;this info as their needs dictate.&#xA;&#xA;&#xA;&#xA;&gt; 5) create a risk profile for users…and flag suspicious behavior (i.e.&#xA;&gt; someone trying to purchase a bunch of stuff that totally doesn’t fit into&#xA;&gt; their purchasing habits).&#xA;&gt; 6) get insurance (although right now reasonably-priced insurance is&#xA;&gt; probably pretty hard to obtain since statistics are generally of little&#xA;&gt; use…we’re entering uncharted territory).&#xA;&gt; 7) set up a warning system and a “panic” button so that if you start to&#xA;&gt; see an attack you can immediately disable all zero confirmation&#xA;&gt; transactions system-wide.&#xA;&gt; 8) independently verify all inbound transactions and connect to multiple&#xA;&gt; network nodes…check them against one another.&#xA;&gt;&#xA;&#xA;Definitely looking at or have implemented this sort of stuff.  I cannot get&#xA;into detail in public...&#xA;&#xA;-- &#xA;Jeff Garzik&#xA;Bitcoin core developer and open source evangelist&#xA;BitPay, Inc.      https://bitpay.com/&#xA;-------------- next part --------------&#xA;An HTML attachment was scrubbed...&#xA;URL: &lt;http://lists.linuxfoundation.org/pipermail/bitcoin-dev/attachments/20150621/8d925c35/attachment.html&gt;</html></oembed>