<blockquote>
  <p>When a user pay the electronic cash to a shop, the procedure between the user and the shop should be executed in an off-line manner. That is, the shop does not need to be linked to the host in user’s payment procedure.</p>
</blockquote>

<p>Neither merchant nor customer need to be connected directly.</p>

<p>A customer can hand a merchant a previously-signed transaction without using a network connection. However, the merchant can only prove the validity of the coin(s) being spent by contacting the network.</p>

CC BY-SA 3.0
2017-08-20T23:24:14.127Z
So, in practice, the merchant would never accept the payment without previously contacting the network... Right?
richard
CC BY-SA 3.0
2017-08-21T03:43:50.673Z
Yes. The payment would only be accepted if the merchant trusted the payee. Even then, it would be wise to consult the network.
Rich Apodaca
CC BY-SA 3.0
2017-08-20T15:46:20.353Z
2017-08-20T15:46:20.353Z
Rich Apodaca
<p>I am studying the concept of <em>Electronic Cash</em>, and in several reference I found that the criteria describing the ideal electronic cash system are as follows:</p>

<ol>
<li>Independence: The security of electronic cash cannot depend on
any physical condition. Then the cash can be transferred through
networks.</li>
<li>Security: The ability to copy (reuse) and forge the cash must be
prevented.</li>
<li>Privacy (Untraceability): The privacy of the user should be
protected. That is, the relationship between the user and his
purchases must be untraceable by anyone.</li>
<li>Off-line payment: When a user pay the electronic cash to a shop,
the procedure between the user and the shop should be executed in an
off-line manner. That is, the shop does not need to be linked to the
host in user’s payment procedure.</li>
<li>Transferability: The cash can be transfered to other users.</li>
<li>Dividability: One issued piece of cash worth value C (dollars)
can be subdivided into many pieces such that each subdivided piece
is worth any desired value less than C and the total value of all
pieces is equivalent to C.</li>
</ol>

<p>Now, what of the above properties are achieved by the Bitcoin system? I guess 1, 2 and 5 are trivially achieved, and I think 3 and 6 are not fully achieved. I wonder if 4 is achieved, and I'm particularly interested in this <em>off-line</em> property.</p>

CC BY-SA 3.0
2017-08-20T11:11:29.933Z
I'm sorry if the tags are not really appropriate, but I think those are the best I could find.
richard
<protocol><payment>
Properties of Bitcoin as an Electronic Cash System
richard
# Properties of Bitcoin as an Electronic Cash System

(Asked by: username_0 on 2017-08-20)

I am studying the concept of *Electronic Cash*, and in several reference I found that the criteria describing the ideal electronic cash system are as follows:

1. Independence: The security of electronic cash cannot depend on
   any physical condition. Then the cash can be transferred through
   networks.
2. Security: The ability to copy (reuse) and forge the cash must be
   prevented.
3. Privacy (Untraceability): The privacy of the user should be
   protected. That is, the relationship between the user and his
   purchases must be untraceable by anyone.
4. Off-line payment: When a user pay the electronic cash to a shop,
   the procedure between the user and the shop should be executed in an
   off-line manner. That is, the shop does not need to be linked to the
   host in user’s payment procedure.
5. Transferability: The cash can be transfered to other users.
6. Dividability: One issued piece of cash worth value C (dollars)
   can be subdivided into many pieces such that each subdivided piece
   is worth any desired value less than C and the total value of all
   pieces is equivalent to C.

Now, what of the above properties are achieved by the Bitcoin system? I guess 1, 2 and 5 are trivially achieved, and I think 3 and 6 are not fully achieved. I wonder if 4 is achieved, and I'm particularly interested in this *off-line* property.

**Tags:** protocol, payment

> **Comments:**
> **username_0**: I'm sorry if the tags are not really appropriate, but I think those are the best I could find.  

---

## 1 answers

### Answer by username_1 on 2017-08-20. Score: 1

> When a user pay the electronic cash to a shop, the procedure between the user and the shop should be executed in an off-line manner. That is, the shop does not need to be linked to the host in user’s payment procedure.

Neither merchant nor customer need to be connected directly.

A customer can hand a merchant a previously-signed transaction without using a network connection. However, the merchant can only prove the validity of the coin(s) being spent by contacting the network.

> **Comments:**
> **username_0**: So, in practice, the merchant would never accept the payment without previously contacting the network... Right?  
> **username_1**: Yes. The payment would only be accepted if the merchant trusted the payee. Even then, it would be wise to consult the network.  

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