19 votes
Accepted

What is the IOTA transaction data structure?

Trinary Note In the "normal" world we have bytes & bits, where 1 byte is 8 bits giving us 2^8 = 256 possible data values for 1 byte. In the trinary world we have trytes & trits, where 1 tryte ...
user avatar
  • 1,663
13 votes
Accepted

Why do some of my transactions have Weight Magnitude 16, although I have set it to 14?

When you perform PoW, you specify "Min Weight Magnitude" (not Weight Magnitude). That means that the PoW will modify your transaction hash until it ends (in ternary) with at least 14 zeroes. As the ...
user avatar
  • 7,254
12 votes
Accepted

How does reattaching a transaction increase the chance for confirmation?

Two reasons: When your transaction is seen by the network, it could be already deep in the tangle (several milestones old) which makes it unlikely to get picked for confirmation. This is often caused ...
user avatar
  • 7,254
12 votes
Accepted

Why does the signatureMessageFragment have a fixed size?

There is no a perfect solution, the both variants (fixed-size and variable-size transactions) have their own pros and cons. These are some pros of fixed-size transactions which make them the best ...
user avatar
10 votes
Accepted

When is a pending transaction technically confirmed?

The validity of a transaction (let's call it target-tx) can be evaluated with this algorithm: random selection of 100 new transaction for each of them: count 1 if there is a path to target-tx (i.e. ...
user avatar
  • 5,344
10 votes
Accepted

Why are transactions so slow?

The issue with the spammer was that it was spamming a single (and commonly used) node and wasn't intelligent enough to distribute transactions among nodes, so it was just overwhelming that one node. ...
user avatar
  • 3,135
10 votes
Accepted

What is an input transaction, and what does its "address" field represent?

It's important to understand that IOTA use UTXO scheme (like bitcoin and probably many other cryptocurrencies). UTXO means Unspent Transaction Output. To understand from where the UTXO concept ...
user avatar
  • 5,344
8 votes

Why is my transaction not getting confirmed?

Some things to make chances better that transactions confirm quickly: Make sure that your transaction is valid (not a double spend) Try to get your transaction propagated as fast as possible after ...
user avatar
  • 7,254
8 votes
Accepted

What does the "block number" in the iota wallet represent?

The two numbers are the the latest solid subtangle milestone index The "latest solidsubtangle milstone" is used for sending transactions. For a milestone to become solid your local node (or whatever ...
user avatar
  • 4,459
8 votes
Accepted

How to know a transaction is "confirmed"?

You can call the GetLatestInclusion convenience function in iota.lib.js. Under the hood, this will first call getNodeInfo to find out the latest solid subtangle milestone hash, and then call ...
user avatar
  • 7,254
8 votes
Accepted

Does every node in the network have to know about all transactions issued by other nodes eventually?

As of the current implementation state, every node will have to receive every confirmed transaction eventually (so that the solid subtangle milestone can increase and the node can calculate all ...
user avatar
  • 7,254
8 votes

What happens if I send money to the wrong address?

Then you basically lost the money. Typos like I<>1 or O<>0 are unlikely to happen, because the address only has [A-Z9] characters. I'm not sure if the target addresses have a checksum on them, I'...
user avatar
  • 921
8 votes
Accepted

Do I Have to Change My Seed after Multiple Transactions?

It's safe to keep your seed. Even if you double-spend or reuse your address, your seed doesn't get exposed, only the private key of one address of your seed is partially revealed. You can generate an ...
user avatar
  • 4,459
7 votes
Accepted

How do I know if a pending transaction will be successful?

The best way, to get your transaction through is to run your own full node on a seperate Server. This makes transactions faster and gives you more control. However, if you don't run your own full node,...
user avatar
  • 1,607
7 votes

How long should it takes before I can consider an outgoing transaction that is still in pending as failed?

There is no green light. If you sign a transaction a second time, even if it is pending, you reveal your private key and the address is insecure. All remaining funds on that address might get stolen. ...
user avatar
  • 1,607
7 votes
Accepted

Is there a difference between branch and trunk transactions?

For most purposes (e.g. determining confirmation status or propagation of transactions) it does not matter which transaction is where. Inside a bundle, however, it is at some places clearly mandated ...
user avatar
  • 7,254
7 votes
Accepted

What is the Min Weight Magnitude and what implications arise from changing it?

IOTA's proof-of-work is formed by successively hashing the data in a transaction, including a nonce, and increasing the nonce until producing a hash which ends with a particular number of zeroes. This ...
user avatar
  • 1,358
7 votes
Accepted

Does every pending transaction pose a threat for my remaining funds in the wallet?

While one single transaction is pending, there is no threat to your balance (apart from the obvious, that if the transaction confirms later, your balance will decrease by the transaction amount). ...
user avatar
  • 7,254
7 votes
Accepted

How to reattach a transaction with no access to sending seed?

Note that the code posted here is not a user-friendly solution, but somebody could easily wrap it up on a webpage with a nice UI. Just give the code the tail hash (i.e. transaction hash of the ...
user avatar
  • 1,358
7 votes
Accepted

What happens to pending transactions after a snapshot?

Transactions that are pending at a snapshot are forgotten, and the balance stays where it is. As the current wallet is stateless, the wallet does not know about those transactions any more either. So,...
user avatar
  • 7,254
7 votes
Accepted

Is it safe to send iota to a pending receiving address?

Addresses are derived deterministically from the seed. In order to receive iotas your address doesn't have to be in "confirmed" state. In fact, You could even decide to not attach your receiving ...
user avatar
  • 363
7 votes
Accepted

Can one send a zero value transaction from any address to any address?

Technically speaking, a zero value transaction (bundle) neither needs to have nor can have a sender address. (Sending transactions in a bundle have value < 0 and receiving transactions have value ≥ ...
user avatar
  • 7,254
6 votes
Accepted

How does a full-node validate transactions?

A full node has a local database of current IOTA balances (which gets initialized from the latest Snapshot and then updated by confirmed transactions). When the full node performs its validation of a ...
user avatar
  • 7,254
6 votes
Accepted

What's the deal with prefixes? Is Mi smallest amount that could be transferred?

What you are referring to as 1 Mi is 1 MIOTA, which stands for 1 million IOTA. 1 MIOTA is the standard traded amount of IOTA on exchanges, but the you can divide it into 1 million single IOTAs which ...
user avatar
  • 3,135
6 votes

What is the average transaction time in IOTA?

As long as the Coordinator is in action, you will have to wait for at least one milestone by the Coordinator (which will happen approximately once per minute) for your transaction to confirm. Apart ...
user avatar
  • 7,254
6 votes

How does a reattached transaction impact the tangle?

A transaction is only an envelope for the signed bundle that details the exact transaction of funds between addresses. The transaction gets attached to the Tangle by doing the Proof of Work and ...
user avatar
6 votes
Accepted

Is it possible to make transactions smaller?

IOTA transactions are less than 4kB, they are currently 2673 trytes which is equivalent to about 1600 bytes or 1.6kB. By far the largest field in the transaction is the 2187 tryte signature/message ...
user avatar
  • 1,358
6 votes
Accepted

How is ensured that a message sent in a transaction is immutable?

Short answer: it is not. Long answer: Signatures are not supposed to protect anything else than the iota values and (obsolete)tag fields. Therefore, as long as your transaction is not confirmed, ...
user avatar
  • 7,254
6 votes

Why confirming 2 previous transactions instead of 1 or 3, 4, 5?

Let me complement the whitepaper based answer with a bit more explicit technical arguments. Confirming just one transaction would lead just to a linked list of transactions - in other words, a ...
user avatar
  • 435
5 votes

How does a reattached transaction impact the tangle?

When you re-attach a transaction you don't take the old one out. You basically issue a copy of the same transaction. So if the yellow transaction is already approved/referenced by the black ones, ...
user avatar
  • 1,663

Only top scored, non community-wiki answers of a minimum length are eligible