Bitcoin Forum

Bitcoin => Bitcoin Technical Support => Topic started by: singpolyma on September 15, 2010, 04:24:53 PM



Title: DNS name tx
Post by: singpolyma on September 15, 2010, 04:24:53 PM
So, we can tx to IPs... can we tx to DNS names?  I don't have a static IP, but I do have DynDNS...


Title: Re: DNS name tx
Post by: jgarzik on September 15, 2010, 04:28:09 PM
So, we can tx to IPs... can we tx to DNS names?  I don't have a static IP, but I do have DynDNS...

tx to IP is not recommended.  Less secure than normal tx.


Title: Re: DNS name tx
Post by: LZ on September 16, 2010, 12:25:36 AM
Yes, but it may be very usable feature. Any ideas how to make it much safer?


Title: Re: DNS name tx
Post by: Gavin Andresen on September 16, 2010, 02:15:21 AM
What is the use case for this?

Is it just to make it easier to send anonymous donations by typing in Pay To: "redcross.org" instead of copying&pasting a bitcoin address?

If something like that were implemented, seems like it would just invite the same kind of abuse we see with misspelled-domain-squatters-- setup a domain record for "redcros.org" pointing to a non-Red Cross bitcoin address and take advantage of people's fat-fingered misspellings.  One big advantage of bitcoin addresses is that they have a built-in checksum, so if you misspell them (or screw up the copy&paste) your attempted transaction will be immediately rejected.


Title: Re: DNS name tx
Post by: singpolyma on September 16, 2010, 01:11:30 PM
The use case was mostly that we have tx to IP (and can only send a memo when going to an IP) and so it seems like whatever reasons there are for sending to IP apply even better to DNS names (for those of us with dynamic IPs).


Title: Re: DNS name tx
Post by: LZ on September 16, 2010, 03:30:17 PM
I want to use SSL for the connection, using the bitcoin address' public key as the cert.
You would be certain you're connected to who you thought, and safely encrypted. The
bitcoin address would not be used for the transaction, only for authentication. A new
generated bitcoin address would be sent through the SSL connection.

Since it's authenticated, it would then be safe to allow the IP address to be a domain
name.  Some care taken that if a proxy is used, it uses socks4a instead of DNS lookup.


Title: Re: DNS name tx
Post by: eurekafag on September 16, 2010, 09:13:05 PM
Sometimes a DNS address resolves to several IPs. Try nslookup google.com. Should we try them all?


Title: Re: DNS name tx
Post by: LZ on September 17, 2010, 05:12:34 PM
I see no problem here. If the node is going to receive bitcoins, there are many ways to do it.
Google may use the routing or port forwarding, or register something like bitcoin.google.com.


Title: Re: DNS name tx
Post by: bitcoinex on September 18, 2010, 07:27:18 AM
Incidentally, for this DNS have custom-built records SRV. Theese records for Kerberos, for example:


$ dig _kerberos._tcp.host.com srv

;; QUESTION SECTION:
;_kerberos._tcp.host.com.   IN   SRV

;; ANSWER SECTION:
_kerberos._tcp.host.com. 3550 IN   SRV   10 10 88 kerberos.host.com.


Requesting for any DNS-name SRV-record in this format, you can find the address of Kerberos-server for this domain. Similarly, we can do for Bitcoin by queryng about: "_bitcoin._tcp.host.com" or something.

All this is done covertly, human sees only the right part of the name: host.com

And for domain names with sub-domains Kerberos using TXT records to enable the customer to understand what realm it belongs to:


$ dig _kerberos.grid.host.com txt

;; QUESTION SECTION:
;_kerberos.grid.host.com.   IN   TXT

;; ANSWER SECTION:
_kerberos.grid.host.com. 3587 IN   TXT   "HOST.COM"


Bitcoin can use this for subdomains like www:

_bitcoin.www.host.com. 3587 IN   TXT   "HOST.COM"

i.e., human can send bitcoin to www.host.com, bitcoin client check TXT _bitcoin.www.host.com for DNS-name of bitcoin "realm", than check SRV _bitcoin._tcp.host.com and, finally, sends bitcoins to IP, specified by this SRV-record.

This scheme is really a part of Kerberos standart and used, I think, more than 15 years.


Title: Re: DNS name tx
Post by: bitcoinex on September 19, 2010, 12:52:32 AM
And this DNS trick will be usable in Tor's .onion network