26

The Bitcoin Improvement Proposal that defines the Bitcoin URI scheme is BIP21. The simple syntax is: bitcoin:<address>[?amount=<amount>][?label=<label>][?message=<message>] On the desktop all of Armory, Electrum and MultiBit respond to Bitcoin URI clicks in a browser and I believe Bitcoin-QT V0.7 does as well. On mobiles Android ...


9

The value of a Satoshi is fixed. The key word is "currently" (smallest currently possible). If the divisibility is ever increased, a Satoshi will still be exactly 0.00000001 BTC, even though there exists unit representing an even smaller amount. There would need to be new names for these new denominations that are even smaller than a Satoshi, but dSatoshi ...


9

Quite concisely, bitcoin is to money what email was to letters . . . and the post office is in trouble.


7

Like Murch said, there isn't a current text based symbol for it, but if you're going to use it on a web application, you can always use Font Awesome. After you include the fontawesome library, you use the bitcoin symbol like this: <i class="fa fa-btc"></i> fa-btc Example output of the code above would be: You can find more information ...


7

I don't know about the rest of the string but I think the leading bytes are ordered that way to make the types of "addresses" be human reconizable. From a quick look at the source I think the leading characters, rpshnaf map like so: r = public Ripple address p = node private s = Ripple secret h = ? n = node public a = address family generator or seed ? f = ...


5

The system is using integers to represent amounts. 1 satoshi is the smallest unit (integer one). The satoshi is the base unit of the protocol (not the bitcoin). It would be very hard to change this to support more decimals, but it seems also extremely unlikely that the need arises. With 21 millions bitcoins (i.e. 2,100,000,000,000,000 satoshi) in total, ...


5

The Bouncy Castle project allows for this and it runs on the Java VM (as was mentioned earlier) as well as the .NET Runtime. An example of using it in C# is shown in this blog post. You can use the .NET version from Visual Basic .NET (as well as any of the other languages on the CLR as well, obviously). For C++, look at the Crypto++ library which supports ...


5

Bitcoin is the currency of the future. In order to understand why this is true, there are two key pieces of information that a person must have: The first is an understanding of how money actually works: how it is created, how it enters the marketplace, and what exactly makes it valuable. The second is an understanding of the Bitcoin community and system. ...


4

Recently I stumbled across this question as I was supposed to explain what Bitcoin was to my 5-year-old nephew. As the question states that it needs to explain the concept of bitcoin to a non-technical person, I took it a step further and explained it to the kid, who knows nothing (literally). So here goes my 2 satoshis on what is the best explanation (...


4

The realistic, honest answer to this question is that Bitcoin is a "Digital Commodity". Bitcoin cannot currently be described as a digital currency since it cannot, practically, fulfill the basic functions of a currency. The wildly fluctuating USD/BTC exchange rate alone means there is price instability. How would YOU like to offer your labour for a few ...


4

I got the common Bitcoin symbol (B with two lines) approved for addition to Unicode as U+20BF last year. It will hopefully become part of the next Unicode standard in June and then it can be used in text. The character (₿) is already supported by iOS and macOS.


4

This is the PR that made OP_RETURN outputs standard: https://github.com/bitcoin/bitcoin/pull/2738 The commit: https://github.com/jgarzik/bitcoin/commit/a79342479f577013f2fd2573fb32585d6f4981b3 The current code: https://github.com/bitcoin/bitcoin/blob/v0.11.0/src/script/standard.cpp#L56-L58 if (GetBoolArg("-datacarrier", true)) ...


3

The denial-of-service (DOS) attack is easy to explain: each time a transaction is updated by increasing the sequence number in an input, the whole transaction needs to be propagated through the network again. So if a transaction is 1 KB and there are 10,000 full nodes, you can waste a minimum of 10 MB of network bandwidth each time you update the ...


3

The Bouncy Castle library provides support for all languages on the Java VM This library (and now a derivative library called Spongy Castle) is used in the BitCoinJ library. The Bouncy Castle library was unfortunately implemented badly in Android which lead to code conflicts that required complex workarounds. Spongy Castle solved those problems making the ...


3

For non-technical users, I found this video to be extremely clear and helpful in explaining the details of how Bitcoin works: How Bitcoin Works Under the Hood


2

I think most people don't get the decentralized part. To explain, I have made a few questions and their answers: how are bitcoins created? how does it prevent double spending? how do we avoid central authorities? Bitcoin is a distributed ledger. Everyone knows how many bitcoins are around and which address sent how many to which address (sort of). A1. ...


2

Bitcoin is a global payment network on the internet. It is self-sustained and allows users to make payments between individuals like cash. Instead of a company being the referee, Bitcoin is governed neutrally by rules asserted through a network of computers running the same open-source software. Bitcoin is completely transparent, in that anyone can see ...


2

I've modified a library for Google Go to support a few of the Koblitz Curves, including secp256k1. It is available here.


2

There's a dedicated C-library for this curve. This is probably the most widely scrutinized library, and it probably has the best performance. Wrappers for other languages are available. https://github.com/bitcoin/secp256k1


2

Update in 2020: The Unicode 10.0 release included the Bitcoin symbol ₿ as U+20BF. For your computer to show the symbol in text, you may need to install a font that includes it. For Linux, one such font is GNU Unifont Glyphs. To my knowledge there doesn't yet exist a single symbol font representation of the B with two vertical lines, although it seems to be ...


2

Using bitcoind and bitcoin-cli you can do it as follows: bitcoin-cli signmessage 1DiWX6p3FdHPZqN88vMeGVXSwAQ1h7BeVj 'Hello world!'


2

I've made a custom font with Bitcoin, Litecoin, and Dogecoin symbols. There's a download link in .otf format in this bitcointalk thread. (It's labeled "Download.") If this font file doesn't include a cryptocurrency symbol that you need, I'm willing to add it.


2

The Hash256 is essentially a uint256. However, after reading through much of the wiki and source, it appears that the Hash256 type is meant to be a generic, unsigned integer type that can store any form of hash that is larger than 128 bits. As an example, all hashes mentioned in the Tree Formats portion of the wiki are stored in Hash256 fields. Some are ...


2

The ledger_index is the 256-bit index of a particular entry in the ledger. The ledger's state tree is a hash tree of index/value pairs. Each index is a 256-bit hash of some kind of locator. If the entry is, say, an account root node, the index is a hash of the 160-bit account ID. If the entry is, say, a ripple balance node, the index is a hash of the two ...


1

Here: bool Solver(const CScript& scriptPubKey, txnouttype& typeRet, vector<vector<unsigned char> >& vSolutionsRet) [...] // Empty, provably prunable, data-carrying output if (GetBoolArg("-datacarrier", true)) mTemplates.insert(make_pair(TX_NULL_DATA, CScript() << OP_RETURN << OP_SMALLDATA)); mTemplates....


1

Here is the unicode for '₿'. paste in any symbol you want the code for. Then hold CTRL+Shift & press 'u' followed by the code it gives. ₿ is 20bf.


1

I think you need something like this <a rel="payment" href="bitcoin:bitcoin_address_is_here?amount=5.00?message=payment to site name"><h2>Pay in Bitcoin now</h2></a>


1

In Bitcoin-qt Or you can do it in blockchain.info/wallet by clicking the menu above your addresses. No need to do it manually.


1

I put together a Kindle book, Bitcoin Step by Step, that covers some best practices. When I was writing I searched the web for what ever I could find trying to make sure what I suggested was indeed the current best practices. You can find it on Kindle.


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