Bitcoin Weekly Newsletter

Bitcoin newsletter

Top new questions this week:

How do I uniquely identify a transaction (to protect against malleability)?

Transactions I broadcast can be malleated by anyone watching the mempool (more info here). This rules out using txid for transaction identification. How can I identify my transactions to make sure ...

mining transactions transaction-malleability mempool  
asked by bvpx 4 votes
answered by StephenM347 4 votes

Speeding up confirmation by double-spending a transaction stuck in mempool

In the context of no-fee transactions that can take a long time to get their first confirmation, is it possible to use raw transactions and double-spend the original transaction by broadcasting ...

doublespend mempool  
asked by ktorn 4 votes
answered by Tom Harding 1 vote

Source code for SPV node on iOS - where to start?

I'm working on a proof-of-concept for a blockchain project and at its core it will need a modified SPV node running on iOS. The reason I need to modify it is so I can build non-standard (e.g. ...

spv ios  
asked by Echelon 3 votes
answered by Bryan Gmyrek 2 votes

What is a mBTC?

I have been trying to find out just what is an mBTC is. Everywhere I look I cannot find out what the value is compared to a Bitcoin. I was hoping you could advise me of what the value is.

terminology divisibility  
asked by jock courtney 3 votes
answered by Murch 4 votes

Can I have multiple OP_RETURN outputs in one transaction?

I am wondering if I can inject multiple OP_RETURN outputs in one transaction?

transactions op-return  
asked by moshaholo 2 votes
answered by StephenM347 6 votes

bitcoin two identical R

Blockchain transaction id 30440220d47ce4c025c35ec440bc81d99834a624875161a26bf56ef7fdc0f5d52f843ad1022044e1ff2dfd8102cf7a47c21d5c9fd5701610d04953c6836596b4fe9dd2f53e3e01 ...

transactions signature hash ecdsa  
asked by Prabu r 2 votes
answered by StephenM347 1 vote

Why are there so many confirmations?

A friend sent me Bitcoin to my blockchain wallet. It shows the amount as part of my balance. However, it says there are 108 confirmations and the number of confirmations keeps going up. Why is this ...

asked by Red Fergus 2 votes
answered by Luca Matteis 4 votes

Greatest hits from previous weeks:

When building bitcoind, I receive error "headers.h:36:20: fatal error: db_cxx.h: No such file or directory"

When building bitcoind on LinuxCoin (Debian based), I receive this error "headers.h:36:20: fatal error: db_cxx.h: No such file or directory" following the instructions at ...

asked by Sean Chapman 15 votes
answered by David Schwartz 6 votes

Bitcoin-Qt setup: Change block-chain file location, settings? documentation?

I am installing Bitcoin-Qt and have been reading about Bitcoin basics, but I found very little information on the client. I have a few questions about the Bitcoin-Qt program (v0.8.1-beta under Windows ...

client bitcoin-qt  
asked by Garrick 12 votes
answered by Nick ODell 10 votes

Can you answer these?

Is Quark as secure as SHA 256?

I'm trying to make certain I'm understanding the purpose behind the Quark algorithm. There are lots of devices that need secure algorithms but have severe power and processing constraints such as ...

hashing algorithms  
asked by Mayo 1 vote

verify satoshi's git signature

the program i am writing to parse the bitcoin blockchain got stuck on block 251718. i hadn't yet implemented support for some of the opcodes in the txout script for tx 24 and i'm now in the process of ...

asked by mulllhausen 1 vote

Bitcoin privacy metrics?

I'm looking for a numerical privacy scoring system that estimate the degree of linkage between the members of a key pool (or even just individual key pairs). Ideally, the method should be easy to ...

asked by Rich Apodaca 3 votes
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