In the past there was a dependence between the value of the coin and the material it was made of, and the more expensive the material was, the greater the value of the coin, whereas today the value of the coin was determined solely in accordance with its nominal value, irrespective of the material it was made of. Nevertheless, the Poskim agree that the current currency, which is a shum'a unit and an accepted form of payment, is defined as a currency. In fact, there is no possibility of defining the current currency as a part of the laws of the Torah, such as the laws of theft and torts, require the use of money, and in any case there can be no reality in which there is nothing defined as halakhic as money.
Unlike a tool whose importance derives from the material and the form in which it is made, the main importance of the coin derives from the ring of the king that turns it into an accepted method of payment.
In this respect, a coin is similar to a banknote, the importance of which also derives from the writing on it and not from the material it is made of. Indeed, unlike a regime, a coin is defined as something whose body is capital, because the state considers it to be a matter of self-worth, and not as a measure whose value is only as a proof of the existence of a debt.
The fact that the material is marginal in the currency is expressed in the words of the Ra'avad :
Because all the things in the world will find in them each sex and each other on the importance of their bodies taste or smell or appearance or that exists other than the currency that is consumed only by his blood in his nest and if there is no benefit in its multiplicity or its rudeness and punctuation ...
These words, which were said at a time when the coins were made of metal with a value, constitute the basis for the poskim's determination that there is no objection to saying that money made of paper will also be regarded as a coin. If this is the case, it seems that one can go a step further and determine that from a halakhic point of view one can completely relinquish the material and define as a coin everything that serves as a waste unit and a means of payment - even if it is something virtual that has no substance at all.
It should be noted that today a large number of transactions are carried out without the physical transfer of coins.
A person accompanies or accompanies the provision of instruction on the computer, while in practice no transfer of money occurs, only a sum of money is recorded as an obligation in the lender's account and at the same time the same amount is recorded as a right in the borrower's account.
Our contemporary posekim dealt with the question of how the borrower buys the lender's money, whereas all that is done is only a drawing on the computer, and this is discussed by the property of Udita, Sittuma, Dinah Dalmukta, etc. The common denominator of all these possibilities is that all of them view the transaction as a debt transfer transaction: the bank owes money to the lender, and when the lender accompanies the transfer, the bank undertakes the same amount against the borrower. It is clear that this definition of the transaction can be correct only as long as there are actually coins and notes of money. In such a reality, the real 'money' is the coins and bills of money, whereas the records on the computer are only evidence of the amount of money that the account holder is entitled to receive. However, if and when the coins and bills of money are completely canceled, and the trade will be conducted through a digital wallet only, the record in the digital wallet will not be evidence of the amount of money, since there is no money except for that registration. In such a reality, the registration in the 'digital wallet' will be the money itself, since it will serve as a monetary unit and means of payment, and as mentioned above, the absence of material does not detract from the halakhic status of the coin.
Moreover, even in a reality where there are still coins and bills of money, as long as the digital payments, which are made without the physical transfer of coins and bills, become more common, they can be viewed as halakhic rather than acts of debt fraud. The digital registration is the money itself, and the increase in the amount recorded in Reuven's account, while reducing the amount recorded in Shimon's account, is the transfer of money from Shimon to Reuven, and not the transfer of the bank's debt to Shimon.
To a great extent there is a similarity between the process that is taking place today and the process that took place in the past, in which the State issued banknotes. At the beginning of the 18th century, the first notes were issued, in order to avoid the need to carry heavy coins made of silver or gold. These bills were in effect promissory notes on the state treasury, for which the state undertook to pay a certain amount of gold. The digital wallet is designed for exactly the same purpose - making it unnecessary to carry coins and bills, and also, in the current situation, allows its owners to receive coins and physical money notes from the bank - according to the registration in the wallet. At the same time that the money notes were issued and they were covered with gold in the state's treasures, the arbiters were divided as to how they should be treated. Some of the poskim who believed that the law is halachically considered to be promissory notes and some of the Poskim saw them as real money.
Since 1968, when the possibility of receiving gold in exchange for the notes has been completely denied the arbitrators agree that the coins and bills of exchange are no longer promissory notes, but are considered money according to Jewish law - even though the value of the material is less than a penny. If we want to apply the rulings of the arbiters in the matter of coins and money notes to the convicted person, it is said that as long as there are coins and notes of money, the bank transfers can be seen as a transfer of debt as a real payment of money, but when the use of coins and bills is completely discontinued The bank is like a real money payment.
It seems that the question whether it is sufficient that the coin is a standard means of payment, or that the government must approve it, is divided into the Chatam Sofer and the Chazon Ish. The Chatam Sofer establishes the halakhic status of the coin currently used to determine the rule.
But a currency fence is decreed by the king upon him to go out and whoever refuses to sell and takes it in the same coin will require his head to the kingdom and Dinah Demalkuta is a true law and justice.
However, the Chazon Ish bases the halakhic status of the coin on public approval:
And the matter of currency is anything that the people of the state agreed to sell and buy in it and to evaluate the entire market as the countries do.
In the opinion of the Chazon Ish, there is no need for the king to issue the coin, and only the king's approval for the use of the currency is required in his country. Without the king's approval, all the people of the state will not accept it as a means of payment. Hence, in the opinion of the Chazon Ish, if the virtual currency becomes such that all members of the state accept it as a means of payment, it will be considered a currency according to Jewish law, even though it was not issued by the government. In the opinion of the Chatam Sofer, however, the consent of the public alone does not grant it the status of currency until the government determines that this is the currency of the state and must be accepted as a means of payment. However, it is possible that even in the opinion of the Chatam Sofer, money will be regarded as money for payments, etc. Even if there is an agreement of the state to use it as a unit of shumah and means of payment.
For Summary,
There is no halachic prohibition to define a virtual currency as a currency - if it was declared a currency by the state.
A currency that the public trusts and views as a means of payment, and a unit may be considered halachically as a currency even if it is not officially recognized by the state authorities - at least in the matter of payments, etc.
The Bitcoin was not issued by the state, and the public's trust in it is limited, and therefore in the current situation it will not be defined as a currency, but as a commodity or as a debt bond.
