user5893: is there any study or recent research of making the bitcoins transfer refundable? As if your account is hacked and the bitcoins are transferred there is no way I can return it back.

user575: What you suggest isn't currently possible with Bitcoin, but it could be added in theory. Mastercoin plans to include this functionality and calls it "saving accounts", though of course it did not originate the idea.
The idea is to have an address associated with two keys, A and B. The address will be used for long-term savings. Funds can be spent from this address only in one of the following conditions:

A transaction is signed by both A and B.
A transaction is signed by A, and there is no "cancelling message" signed by B within X hours.

Furthermore, the transaction outputs cannot be spent before X hours pass.
These addresses will be recognized as savings addresses and merchants will not accept payment directly from them. They are used only for long-term savings, to be eventually moved to a hot wallet for everyday use (after X hours).
This arrangement has the following security features:
 - To lose the coins, you must forget key A.
 - To steal your coins, the attacker must steal keys A and B, or the attacker steals A and you forget B.
That's a different configuration from normal addresses and multisig addresses, which may be advantageous in some scenarios.

user6679: At the technical level - No. 
Credit card charge-backs work because the credit networks such as VISA and MasterCard (and participating banks) are giant clearing houses or multilateral bank arrangements to that effect. Anyone with an ongoing relationship with a bank essentially agrees to having money removed from their account or frozen in the case of a dispute or other funny business. 
This is difficult to enforce with bitcoin addresses, if those addresses avoid the more centralised parts of the bitcoin ecology (currency exchanges, escrows, off-block payment gateways) that are more motivated to trace, penalise and report theft and fraud.
However:

Bitcoin insurance may become a popular way to mitigate against theft or fraud. This should actually be quite easy for insurance companies to calculate actuarial tables and premiums for; as the global transaction log for this currency is entirely visible.
Escrow is a common option for "reversible" transactions but only because the atomic irreversible bitcoin transactions are split into two separate transactions: One to the escrow and one from the escrow - assuming the escrow service is more trustworthy than the original buyer/seller arrangement... Escrow can provide a potential reversible service for fraud but would be pretty useless against theft.
A bounty arrangement might be viable. As actually offloading the bitcoins to a fiat currency is hard to hide (unless your mixer service provides pools of large volume and uniform dispatch interval); offering a bounty or amnesty of X% of the stolen money might result in the thief returning it.


5893: <p>is there any study or recent research of making the bitcoins transfer refundable? As if your account is hacked and the bitcoins are transferred there is no way I can return it back.</p>
 575: <p>What you suggest isn't currently possible with Bitcoin, but it could be added in theory. Mastercoin plans to include this functionality and calls it "saving accounts", though of course it did not originate the idea.</p>

<p>The idea is to have an address associated with two keys, A and B. The address will be used for long-term savings. Funds can be spent from this address only in one of the following conditions:</p>

<ul>
<li>A transaction is signed by both A and B.</li>
<li>A transaction is signed by A, and there is no "cancelling message" signed by B within X hours.</li>
</ul>

<p>Furthermore, the transaction outputs cannot be spent before X hours pass.</p>

<p>These addresses will be recognized as savings addresses and merchants will not accept payment directly from them. They are used only for long-term savings, to be eventually moved to a hot wallet for everyday use (after X hours).</p>

<p>This arrangement has the following security features:
 - To lose the coins, you must forget key A.
 - To steal your coins, the attacker must steal keys A and B, or the attacker steals A and you forget B.</p>

<p>That's a different configuration from normal addresses and multisig addresses, which may be advantageous in some scenarios.</p>
 6679: <p>At the technical level - <strong>No</strong>. </p>

<p>Credit card charge-backs work because the credit networks such as VISA and MasterCard (and participating banks) are giant clearing houses or multilateral bank arrangements to that effect. Anyone with an ongoing relationship with a bank essentially agrees to having money removed from their account or frozen in the case of a dispute or other funny business. </p>

<p>This is difficult to enforce with bitcoin addresses, if those addresses avoid the more centralised parts of the bitcoin ecology (currency exchanges, escrows, off-block payment gateways) that are more motivated to trace, penalise and report theft and fraud.</p>

<p><strong>However:</strong></p>

<ol>
<li><p><em>Bitcoin insurance</em> may become a popular way to mitigate against theft or fraud. This should actually be quite easy for insurance companies to calculate actuarial tables and premiums for; as the global transaction log for this currency is entirely visible.</p></li>
<li><p><em>Escrow</em> is a common option for "reversible" transactions but only because the atomic irreversible bitcoin transactions are split into two separate transactions: One to the escrow and one from the escrow - assuming the escrow service is more trustworthy than the original buyer/seller arrangement... Escrow can provide a potential reversible service for fraud but would be pretty useless against theft.</p></li>
<li><p>A <em>bounty arrangement</em> might be viable. As actually offloading the bitcoins to a fiat currency is hard to hide (unless your mixer service provides pools of large volume and uniform dispatch interval); offering a bounty or amnesty of <em>X%</em> of the stolen money might result in the thief returning it.</p></li>
</ol>
