Is there any part of a bitcoin transaction that is 'random' or could not be predicted?

Question

I am just curious if when a transaction is sent and you view it on the blockchain. Is any of that information impossible to predict what it will be?

I am looking at perhaps the time received ? (you may be able to guess close but maybe not down to the second?) or the relayed by ip?

Does that make sense? I am guessing not since according to: Are transaction hashes random? the transaction hash is not random, but still want to clarify.

Likewise, looking at the coinbase api:

GET https://coinbase.com/api/v1/transactions/5018f833f8182b129c00002f

# Response
{
"transaction": {
"id": "5018f833f8182b129c00002f",
"created_at": "2012-08-01T02:34:43-07:00",
"amount": {
  "amount": "-1.10000000",
  "currency": "BTC"
},
"request": true,
"status": "pending",
"sender": {
  "id": "5011f33df8182b142400000e",
  "name": "User Two",
  "email": "[email protected]"
},
"recipient": {
  "id": "5011f33df8182b142400000a",
  "name": "User One",
  "email": "[email protected]"
}
 }
 }

Could the 'created_at' time be considered random?

Thanks.

Answer 1

There is always an inherent way to control the transaction. Try to create it, if you don't like the result, try again.

If your game gets popular enough, it may be economically viable to effectively spend computing power on mining transactions that game it.

Answer 2

It depends how the transaction is formed. Typically, the signature is random and unpredictable, but nothing stops someone from using a wholly deterministic algorithm. The time received is not part of a transaction -- how could it be?