Question on offline wallets

[medtech]

Hi


If I have an offline account it would contain 100 private keys (addresses?) if generated by multibit.  whenever someone transfers to me, one of these addreses gets used.  If I use all my keys I have to go online to generate new ones, right?

So the question is. What happens if someone spams 100* minimum transfers to my offline account just before I am to recieve a big transfer?

[zimmah]

you don't HAVE to use a new key for every transaction.

it's advised to do so for privacy reasons, but your public key is just like your bank account, once someone knows your bank account number, they can transfer money to it, but they can't withdraw money from it.

once someone knows your bitcoin address, they can transfer money to it, but they can't withdraw money from it. and multiple people can transfer money (bitcoins) to the same address.

only online shops usually generate a new address for every transaction, but this is mostly to automatically know which order matches with which payment. If order #0001 pays to adress 1DSGg342tg4Ht4ghrh and order #0002 should pay to address 1f34Gd7g4gbHefvbt32S6hh but doesn't pay, than the owner of the webshop immediately knows which order paid and which one didn't. simply because the first address has bitcoins in it, and the other does not.

also, NEVER give anyone your private key. (private key starts with a 5) it's only for your own use, it's the key to unlock your bitcoins and pay with them.

if you want someone to pay you money, simply give them only the public key, (starting with a 1)

[DannyHamilton]

(private key starts with a 5)

Or a L or a K

[DannyHamilton]

If I have an offline account it would contain 100 private keys (addresses?) if generated by multibit.

I don't think MultiBit pre-generates 100 keys?  I thought MultiBit only generated keys as needed?  Did this change, or did I misunderstand?  Can you link to where you got this information?

whenever someone transfers to me, one of these addreses gets used.

That assumes that you give each person a different address to send to.  While that is the recommended procedure, there are many people who prefer to re-use the same address multiple times.  Re-using addresses reduces privacy and security, but it generally works fine.

If I use all my keys I have to go online to generate new ones, right?

You do not need to be online to generate keys or addresses. This can be done offline.

The wallet takes care of generating the keys for you whenever you request a new address.  If you don't want a new address, then the wallet won't generate new keys.  If you do want a new address, then the wallet will generate a new key pair to create the new address.

So the question is. What happens if someone spams 100* minimum transfers to my offline account just before I am to recieve a big transfer?

How is that person going to know what your addresses are unless you tell them?  Why would you send someone all of your current addresses?

Regardless, if this happened, then the address that you give out for the "big transfer" will receive 2 payments.  One from the spam, and another from the "big transfer".