Credit cards

In the twentieth century, customary money began to change. With the formation of the trade boom in the 1950s, a system of non-cash settlement appeared. There were special bank cards. In the 1970s, a magnetic strip was applied to them, and in the late 1990s these chips began to be embedded in chips.

Initially, the cards belonged to very rich people, allowing them to receive unlimited credits. At the same time there were also scammers who use this.

Today, bank cards are very common, because with their help you can make payments in any country in the world without carrying bundles of banknotes. But there are people who prefer to work exclusively with cash. They are frightened by myths about bank cards. We will consider these errors.

Credit cards

On the card itself, the rest of the money is stored in the account.

In fact, on a normal debit card, even if it is chip-based, and even more so on a credit counter there is no money. After all, the card performs the function of an identifier. Of course, there are exceptions. Some cards with a chip have applications-wallets. This can be a discount program, virtual facilities (for example, fuel liters). But this is not directly related to the normal use of the card. Yes, and activate these applications can only be in special outlets that support this unique type of cards.

If the store wants to accept payments using bank cards, then it will be necessary to connect to the international system – Visa, Mastercard, etc.

No one will directly connect directly to these large payment systems. This is available to either independent processing centers or large banks. After all, cooperation with Visa or MasterCard implies special expensive equipment, safety certificates, impressive insurance bills and other nuances. Not every bank is capable of such wasting. So those wishing to accept cards will have to use the services of local banks.

Terminals for accepting payments or ATMs are connected directly to Visa or MasterCard.

Large international payment systems do not have their own ATMs or payment terminals. All of them necessarily or belong to some bank or through them have the opportunity to connect to the global payment system.

There is a certain amount on the card. That’s it and you can spend it.

In fact, the balance on the account and the amount that can be spent for the day are not particularly related. It is better to talk about the daily limit on the map. But it depends on a lot of factors and there may be more balance on the account, and less of it. Even if the account is an amount of several million, the system is unlikely to allow a day in a day to take more than a few thousand. And this is not a hardware limitation of the ATM itself. On the other hand, a particularly valuable customer who has an impressive account can, if necessary, make a call to the bank and significantly increase his limit. Today, by the way, reasonable changes to the daily limit are available to most customers on a call with authorization. The bank can take responsibility to slightly change the rules.

The PIN code of the card checks either the ATM itself or the payment terminal.

Almost always, the use of a card implies a connection to the bank that issued it. Even if the Sberbank card will be used in an American ATM, a request to Russia will be sent to verify the PIN. Such a system works precisely because the code can only be checked by the bank that issued the card. The only exception is cards with a chip. They can check the PIN themselves, because the chip card is essentially a minicomputer, which also performs encryption functions. Sometimes when using cards to pay for a purchase, and not when withdrawing cash, the outlet may not even contact the authorization center for each purchase. This can happen if the amount is less than a certain limit.This is relevant for small amounts, when the value of the purchased goods is less than the exchange session on the electronic channel with the bank will cost. As a result, taking into account small amounts, you can use daily counters for authorized cards. After all, the risks of large losses due to fraud are not due to the size of transactions.

Credit cards

PIN-code is written on a magnetic strip, it can be stolen by any cheater, it is only the card that gets him in his hands.

On the magnetic strip, the cryptographic verification of the PIN and the card number, which is obtained with the help of a cryptographic key stored under guard in the bank, is actually done. In other words, with the help of data from the magnetic strip, the PIN can only be checked, and even then, knowing only the super secret key. Usually, the data is encrypted using the 3DES algorithm. The most protected “key” is a hardware device for storing data and performing cryptographic operations with them. In other words, after the initial input of keys into this device in a pure form, they do not go outside. In addition to the usual protection of such devices, they are also equipped with protection against penetration. If you just try to open the case to install a “bug”, all the keys will be immediately destroyed automatically.

The technique of initial key input is also interesting.

To begin with, select several bank security officers. Ideally, they should not know each other personally. Everyone generates his own version of the key, not showing it to anyone. Then they take turns to enter the room where the key storage equipment is located and enter their data. When all keys are entered, the device conducts an XOR (logical addition) operation between them. So the final key is formed, which is written to the device. It turns out that nobody knows him at all. To recover, you need to obtain the initial data from each of the selected employees who undertake to store this confidential information. And do not think this level of security is excessive, sometimes you need to include administrative measures, because cryptography can sometimes be defeated by a simple human factor.

PIN code can be reported to bank employees.

No employee of the bank should ever ask the customer’s PIN. However, often the users themselves when calling in the bank answering a secret question (it is formed when opening an account) call their PIN-code.

After making a purchase, the money is immediately transferred from the client account to the store account.

In fact, the real exchange of electronic funds occurs only at the end of the working day. And at the time of purchase, only the “spent” amount is blocked. The actual write-off will happen in a few days, when the bank-owner of the account receives a financial confirmation from the bank through whose terminal the payment was made.

The amount that is inscribed in the check after payment by the card will be exactly deducted from the account.

In fact, the amount written off during authorization may be different from that which will be written off during the financial transaction. This is especially true when paying for hotels or renting cars. It happens that retail outlets can write off some extra expenses afterwards. This may be a shortage of gasoline or an unpaid breakfast. These are just some of the outlets that are allowed to increase or decrease the final amount. The amount blocked during authorization may also differ from that which will ultimately be debited from the account if the account currency differs from the transaction currency. The fact is that the actual write-off occurs in 1-2 days, during the same time the conversion rate may change slightly.

The amount blocked on the account after payment by the card will be written off sooner or later.

In fact, the amount blocked at authorization can be never written off from the account. For an ATM, the critical deadline is 10 days, and for other terminals – 45.If the bank does not receive a financial confirmation of the operation from the payment system used by the person during this time, the money will be unlocked. There are in this and its pluses and minuses. Advantages lie in the fact, if an operation was performed, from which it is required to refuse. Then, after a call to the bank, you can explain the reason for the refusal, if possible, the operation will be canceled and the lock will be removed. True, if the bank receives financial confirmation from the outlet, it will have to be dealt with independently, without the involvement of the client and his funds. The disadvantages lie in the situation when the client applied to the bank after receiving a financial confirmation. Then cancel the operation will be more difficult. The bank will have to start an official investigation, which can drag on for 45 days. And all this time the purchase amount will remain blocked, inaccessible to the client.

Credit cards

If a person owns a debit card, then he can not be owed his bank.

It seems logical that the owners of credit cards can go “in negative.” But is this possible for debit card owners? In fact, as already mentioned, the logic of authorization is based on not the real amount on the account, but on the daily limits. So, the owners of credit cards, and debit ones can eventually climb into the negative. This happens if the bank sets daily limits, which will slightly exceed the balance on the account even for debit cards.

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