And the banknotes that Zhang Nan wants to take out are different, although Datang has now been able to make cheap paper, but the technology of this cheap paper is still firmly in Zhang Nan's hands, and even the officials of Datang don't know about it.

Zhang Nan gave the papermaking business to Cui Shao, which is equivalent to giving it to the Cui family, although the Cui family is a big family, but Zhang Nan believes that Cui Shao will not be stupid enough to take out such real money to others.

And although the factory is in the hands of the Cui family, only two people know the real papermaking technology, one is Zhang Nan, and the other is Cui Shao, who Zhang Nan gave the formula.

The work in the paper mill is distributed, and these workers only know the steps of their work, as for the previous step or the next step, they do not know, which also ensures that the cheap paper made by Zhang Nan will not be known by the outside world.

Although Comrade Li Er really wanted to use such cheap paper to contain the family, it was not the time, and now the family and the royal family got along more harmoniously, so Zhang Nan still chose to hold this technology in his own hands.

This is more reassuring for Li Er, or for other families, although ordinary people can now afford this thing of paper, but for the family, as long as Li Erli does not have the technology to get this cheap paper, they can be more comfortable.

"Your Majesty, since copper coins are so easy to counterfeit, our banknotes can ensure the authenticity of the currency to the greatest extent." Zhang Nan said.

"Are you so sure that this note can't be faked sooner? In my opinion, this banknote counterfeiting is simpler, you think, now ordinary people in Datang can buy your cheap paper at will, isn't it easy to counterfeit? Li Er wondered.

"No, no, no, your majesty, you are too worried, the paper that the minister took out is very different from the paper sold on the market, this paper can not be broken even after being wet, and it also has better toughness to ensure its use time." Zhang Nan said.

"Doesn't it break when it meets water? Where is such paper? I don't believe it. Li Erdao.

"If you don't believe it, Your Majesty, you can try it." After Zhang Nan finished speaking, he took out a green Grandpa Mao, although Zhang Nan wanted to take a red Grandpa Mao out at first, but helplessly, the face value was a little big, and Zhang Nan was also a little reluctant.

Li Er took the banknote in Zhang Nan's hand and looked at it carefully.

"Qingquan, aren't you in the frame? Where is this banknote, this is clearly a painting, this portrait is so lifelike. Li Er took a pen and paper and looked into the air and said.

"This is the banknote, and the painting on it is just the design style of the banknote." Zhang Nan said.

"Oh? So, is this the banknote you got through the door? So who is this person? Li Er looked at the avatar on the banknote and asked.

“...... Well, this is a great man who passed through the gate, and in honor of him, we pass through the gate to print his portrait on the banknote. Zhang Nan thought for a while and said.

When Li Er heard Zhang Nan say this, he immediately stopped talking, and then there was a strange light in his eyes, Zhang Nan knew too well what this light represented.

"If the emperor likes it, when our Datang banknotes are designed, you can also print your portrait of the emperor." Zhang Nan said helplessly.

"Good! What I want is your words, yes, deep meaning, so let's make this note out and let me see it, if it's really feasible, we'll discuss it. Li Eryi heard that Zhang Nan could also print his portrait on the banknote, and he immediately became happy.

"Okay, that's all for today's discussion, tomorrow, Qingquan, you hand me an excerpt, the bank's affairs can be put on the agenda, compared to our Datang needs a lot of money to develop our technology and construction." Li Erdao.

"Obey." Zhang Nan arched his hand and said.

After returning to the house, Zhang Nan came up with an excerpt that combined with the actual situation of Datang to build a bank, and the name of the bank was called "Datang Bank". In fact, Zhang Nan wanted to call it "Chang'an Bank" at the beginning, but this bank is oriented to the whole Datang, so it seems a little childish to call it Chang'an Bank, and in the end Zhang Nan still denied this idea.

Although the bank's idea is good, but the actual operation is still very difficult, the first is to solve the problem of saving and withdrawing money, Datang does not have a network system, so how to unify the access of the major state capitals is a big problem.

Although Zhang Nan also designed the passbook, but this thing is relatively inconvenient, and the identity certificate is also a difficult thing when withdrawing money, there is no network system, then there is no way to set a password, there is no password and there is nothing that can prove the identity of the head of the household, which causes great inconvenience to withdraw money.

Zhang Nan thought about it for a long time, but still didn't come up with a good solution to this problem.

During dinner, Cui seemed to see that Zhang Nan had troubles, and then asked Zhang Nan what happened, and Zhang Nan also told Cui 1510, after all, there is nothing to hide.

Unexpectedly, after Cui listened to Zhang Nan's troubles, he chuckled and said: "Lang Jun, on weekdays, the concubine thinks that you are the smartest person in the world, why are you confused now." ”

When Zhang Nan heard Cui say this, he was also puzzled, and then asked, "Is it possible that you have any good methods?" ”

"Of course." Cui said with a smile.

"If you have one, say it quickly." Zhang Nan said.

"Isn't that simple? Lang Jun, do you remember the ID card you gave me over there? Wouldn't it be better for you to ask the bank to take this with you when you deposit and withdraw money? Although our Datang is not as advanced as yours, isn't it simple to provide something to prove your identity? Cui looked at Zhang Nan and smiled.

Zhang Nan patted his head after hearing this, how could he forget this way?

Although it is still a bit unrealistic to apply for ID cards for the people of the entire Tang Dynasty, it is still very simple to apply for an identity certificate for the people who deposit money in the bank, and this identity certificate can also be written on the password used by the head of the household to withdraw money.