Imperial Senator Mon Mothma has deposited a large amount of assets in the bank.
The Empire knows the actual state of the assets and monitors how they are used.
The reason for the existence of the Senate is its abundant funds.
The Empire wants to centralize the assets held by the Senate. If they can control the flow of funds, it is convenient for the Empire. Since it is an enormous amount, if it is not used for the Empire's benefit, it will be a security problem. The Emperor was concerned.
It was not easy for Mon Mothma to transfer a huge amount of assets to another account under this surveillance. He has no intention of using it for the Empire's benefit, and intends to violate the law.
Tey Kolma will escape the Empire's surveillance and use it as a source of funds for rebellion activities. Donation on the surface.
Of course, it will not be managed in one place, but will be decentralized. He will use a false name so that the Empire does not notice. Lucen will withdraw from one of them. He wants it so badly. Lucen's method of deceiving the Empire by himself was convenient for concealing the source of funds.
Lucen used large sums of money to buy information, hire operatives, and carry out his operative activities. They were so sporadic that the Empire did not notice.
A network was built over many years of operative activities. If some of them fell into the hands of the Empire, they could simply cut them off. No one in the network knew who "Lucen Rhayel" was, and the true nature of the operative activities should not have been exposed. This would not have been possible without Mon Mothma's assets.
The network even infiltrated the Empire, and several Imperial officers provided information evading the Empire's eyes. In return, they would provide the Empire with useful information or a reward. They would infiltrate the core and promote them.
Cassian and the other elite operatives agreed to the cause of "Hope".
They withdrew funds for operative activities from one of the accounts Lucen had informed them of. They would never run out, which was reassuring.
Even if they suddenly needed to buy expensive information, they would have it ready.
All of the network's operations are funded by Mon Mothma's assets, most of which most operatives don't know, and are the founding funds of the Rebel Alliance.