@TheRealSteve, That table of start delivery date and price is great (http://www.vnbitcoin.org/bitcoincalculator.php).  Exactly what I am looking for.  Thank you so much.

@philipma1957 That is great info on antminers.  A lot of thanks, .

@TheRealSteve, thank you, your thread on StickMiner does have a lot of history about the historical price.  pretty nice.  is there any equivalent for regular miners?

yeah, i can find wiki with mining machine spec (https://en.bitcoin.it/wiki/Mining_hardware_comparison), but unfortunately, not the historical price and availability date.

Is there a way to find historical mining machines information? 

eg. on what date do mining machines become available and what is the price?
or instead of the date that it becomes available, what date does the company advertise it to be available. 

This is for an interesting research exercise. 

Appreciate it if anyone can offer some information.  I have not yet find a website that gives these data. 

FYI. The pull request filed earlier.
https://github.com/bitcoin/bitcoin/pull/6659

Thanks for the inputs, amaclin and DannyHamilton.

1) Increase the tps that a node can process.  It seems that our test machine cannot process more than 15 transactions per seconds (not talking about mining or blocksize).
3) My friend has the change already and can submit a pull-request.  

It seems that we might be able to optimize some transaction checkings. 
Many checkings are done twice:
1. when the transaction is placed into the pool
2. when verifying validity of the transaction in a block

Why don't we simply check if the transaction in a block is already in the memory pool?  The transaction is already verified when it is placed into the pool. 

Does this makes sense?  If so, is there a reason that bitcoind does not want to do this?   

Thank you very much for your review.

Care to elaborate more?   

blockchain

Is it possible to encrypt a message so that only a certain address owner can read it? 

I guess there are two parts of the questions. 

1. I may not know the public key from the address because address is hash of public key.

From my understanding, the public key wouldn't be revealed until they have made a transaction. 

If I do not have the public key of the recipient, I guess I cannot do anything about it.

2. Let's say I do have the public key of the recipient address.  Could I then encrypt the message with the public key such that only the private key owner can read it?

Assuming that the address owner has revealed the public key in order to make a transaction, then we can find the public key from blockchain.  With this assumption, then we should be able to do this?

 

I vote for Design Two by S4VV4S.

i also would like to know if there is any known implementation of this protocol. 

Appengine is a different animal from Amazon aws or a regular hosting service.  appengine does not allow you to run everything.  It is not a vm-like box, but it gives you several benefits in other areas for those tradeoff. 

Amazing.  That fixes my ufw issue.  That also fixed my other connections issues.  For example, connecting from ssh took 20-30seconds to connect after ufw is enabled.  that is also fixed.  
Thank you very much Morblias.  

I am running into an error while executing
  $ ufw enable

------------------------------------
Longer version:

I am running this on weloveservers.net and I have done a complete wipe out and re-install OS from the control panel. 

I am running this on ubuntu 13.10 now. 

Following the instruction, I am executing (instead of executing the script, I run line by line on command line):

  $ ufw --force enable

I am getting:

ERROR: problem running ufw-init
libkmod: ERROR ../libkmod/libkmod.c:505 kmod_lookup_alias_from_builtin_file: could not open builtin file '/lib/modules/2.6.32-042stab090.3/modules.builtin.bin'
FATAL: Module nf_conntrack_ftp not found.
libkmod: ERROR ../libkmod/libkmod.c:505 kmod_lookup_alias_from_builtin_file: could not open builtin file '/lib/modules/2.6.32-042stab090.3/modules.builtin.bin'
FATAL: Module nf_nat_ftp not found.
libkmod: ERROR ../libkmod/libkmod.c:505 kmod_lookup_alias_from_builtin_file: could not open builtin file '/lib/modules/2.6.32-042stab090.3/modules.builtin.bin'
FATAL: Module nf_conntrack_netbios_ns not found.
ip6tables-restore: line 4 failed
ip6tables-restore: line 65 failed
ip6tables-restore: line 69 failed
sysctl: permission denied on key 'net.ipv4.tcp_sack'

Problem running '/etc/ufw/before6.rules'
Problem running '/lib/ufw/user6.rules'


Some googling showed that this kind of issues could occur on OpenVZ.  Some people recommend commenting out rules in before6.rules and user6.rules. 

Did any of you see have issue executing "ufw enable"?  Or it is just me?  Which OS version did you choose?  I am using ubuntu 13.10. 

Thanks ahead...

If bitcoin value increases a lot, more decimal place can be introduced.  Transaction fee can be changed as well.

use "payment channel" contract capability.  it is a complicated process.  someone still has to make it easy to use. 
https://en.bitcoin.it/wiki/Contracts#Example_7:_Rapidly-adjusted_.28micro.29payments_to_a_pre-determined_party
https://bitcoinj.github.io/working-with-micropayments

thanks, i did not limit the number of connections.  maybe that is why.  i will try limit maxconnections. 

I believe bitcoinj runs in SPV mode.  So i don't think it downloads blockchain.  bitcoinj does have full verification mode, but that mode is experimental.  source: http://bitcoinj.github.io/#getting-started

I used weloveservers' vps node and put a bitcoind on it.  The vps has went down a couple of times, weloveservers support mentioned that it is getting ddos'ed.  Did anyone experience similar issue?

also Kraken, along with a few others.