Can I use single address for all my transactions? Can I always use single public key (addr1) for all my transactions and when I spend every time protect it with different scripts / keys (key2, key3, etc.), so that spending requires at least two keys ('key1', and 'key-n') but addr1 remains the same for receiving bitcoins.

example.

(transaction, output script): (input address, amount) --&gt; (output 1); (output 2)
--------------------------------------------------------------------------
(trxn1, script1): (addr1, 10 BTC) --&gt; (addr2,  5 BTC); (addr1,  5 BTC)
(trxn2, script2): (addr1,  5 BTC) --&gt; (addr3,  1 BTC); (addr1,  4 BTC)
(trxn3, script3): (addr1,  4 BTC) --&gt; (addr4,  1 BTC); (addr1,  3 BTC)
(trxn4, script4): (addr5, 12 BTC) --&gt; (addr1, 10 BTC); (addr5,  2 BTC)
(trxn5, script5): (addr1, 13 BTC) --&gt; (addr6,  2 BTC); (addr1, 11 BTC)


Is it possible to make script 1, 2, 3 and 5 would require different keys (at least 2; key1 and key-n) to spend bitcoin from this address?

Is it possible with Script? Is there any other ways in which I can keep single address for all my transactions?

addr1 is my address; transactions 1, 2, 3, 5 are my spends and transaction 4 is receiving transaction.



Motivation: To use same address for all my transactions. Reason is, I own firstbits address '1vijay', and I don't want to loose in case of my private key compromised. I am looking for any solution that would solve my problem, particularly scripts.

pseudo-script would be something like,

scriptPubKey: &lt;pubKey1&gt; OP_DROP &lt;pubKey2&gt; OP_CHECKSIG
scriptSig: &lt;sig&gt;


I would like to use 'pubKey1' as my receiving address always, but my spending would depend on private key corresponding to 'pubKey2'.
If you are to receive a transaction with address A, you need A's private key in order to spend it and nothing more.

If you want to require two or more addresses to be used to spend money you receive, you would need to use a multisig address. After that, you would need to use m-of-n private keys to spend the coins, with m and n being predefined when you create the multisig address.

There are other ways one could restrict coins from being spent - say requiring a password or allowing anyone to spend them, but they are a lot more obscure and generally not used by anyone.