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"In fact, a one-way trapdoor function with exponential power operation is constructed, and the ciphertext C = m ^ emodn" is obtained by calculating plaintext M.

"but it is difficult to calculate the base number m from ciphertext C, exponent e in reverse calculation. Unless you know the trapdoor information D

“……”

Martin Hellman talks about the details of the story.

The expression of the crowd also changed from a blank face to a surprised face, and then to a sudden realization.

There is a saying that a fool is only one teacher away from genius

When Martin Hellman leads the crowd into the gate, they suddenly feel cheerful.

It turns out that the public key cryptography technology is not as difficult as expected.

And the source of this difficulty comes from the threshold!

Yes, the threshold.

Every profession and every subject has a threshold.

There is an easy to understand term for this threshold, which is called "Introduction".

The people sitting here are top talents from universities or institutes.

They have enough knowledge in their heads to go around the Earth twice.

The reason why they feel difficult in the face of public key cryptography is that they have not crossed the threshold!

Sometimes, to solve a problem is actually very simple, just need to catch that fleeting pigeon.

Just trying to catch him is extremely difficult.

Now, Martin Hellman brought the pigeon to the public.

People have no reason to refuse

On the stage, Martin Hellman's mouth rose, looking at the expression of people's sudden realization, his face quietly hung with a faint smile.

To be honest, he was very happy, very happy.

Because that's the nature of science.

This is the original intention of his invention of public key encryption technology.

He wants to make this technology known and used by more people.

Martin Hellman raised his mouth slightly and said slowly: "we talked about the algorithm architecture just now, and now we will talk about the solution adding technology..."

"As the name implies, encryption technology is to encrypt the program, [encryption] C = m ^ emodn, RSA is block cipher, for a certain n, plaintext message is converted into binary data, and is divided into data blocks smaller than n."

[decryption] proves that:

C ^ dmodn = m

C ^ dmodn = (m ^ emodn) ^ dmodn

= (m ^ (ED) MODN ^ D) MODN

= m ^ (K Φ (n) + 1) MODN

"

=M ^ (K Φ (n)) * mmodn (Euler extension of Fermat's small theorem)

= 1 * mmodn

= m "

after decryption, each group of ciphertexts is the result of module N operation, so it is also a number less than n. However, the number of digits in each group of ciphertexts is indefinite. The n-bit can be filled with the method of filling 0. "

“……”

Quiet!

Dead silence

Listen to Martin Hellman talking on the podium. There was no sound.

At the moment, their hearts have set off a towering wave.

They wanted to scream.

But the only examples left tell them they can't!

Because it's likely to disrupt Martin Hellman's mind!

So they can only try their best to suppress the waves in their hearts and pretend to be calm and calm and listen to Martin Hellman's report.