Chapter 105 On-site Verification
All the cryptography experts in the room were focusing on the verification of the MD5 cryptographic algorithm at the moment, and they would not run to the spare lecture hall next door. After Biham said this, no one stood up.

Although the host was a little embarrassed, he always kept a smile on his face.

Don't dare to have any opinions.

As a world-recognized top cryptography expert, it was a great honor for the organizers for Biham to attend the conference. Even if the president of the International Society for Cryptologic Research was here, he would have to speak politely, let alone them, who are ordinary conference staff.

Seeing that he couldn't finish the report, Xu Yuan simply stayed on the stage and waited for others to verify it.

Anyway, the total of more than sixty verification steps is not troublesome.

The host just didn't know to bring a chair up, and he really didn't like his lack of tact.

Time passed by minute by minute, and the huge lecture hall suddenly turned into an examination site. All cryptographers carefully entered the values, fearing the slightest mistake.

Otherwise, the verification results will be biased, which will be a loss for the entire cryptography community.

Xu Yuan and Wang Xiaoyun in the audience were the most relaxed and comfortable at this moment because they already knew the result.

Another half hour passed.

Professor Biham finally completed all the verification steps and stood up from his seat again and said, "I have to admit that today is the best report I have heard in more than ten years. The collision method you used has brought hash functions to a new milestone."

"Thank you for your contribution to the study of cryptography."

He paused here, then leaned over to express his gratitude under Xu Yuan's unexpected gaze.

Upon seeing this, Xu Yuan quickly responded in English: "Professor Biham, as newcomers in the field of cryptography, it is our honor to promote the development of cryptography."

"You're pretty good." Biham said with a smile.

But as soon as he finished speaking, his expression was suddenly replaced by regret, and he sighed and said, "But unfortunately, the MD5 result is not accurate."

Xu Yuan's expression remained unchanged after hearing this: "Don't worry, Professor Biham, it must be correct."

"The verification result I got is wrong. The MD5 password was not cracked successfully." After hearing Xu Yuan's very confident words, Biham shook his head to confirm again.

Desmed, who was still calculating in the audience due to an arm injury, paused when he heard this and a look of disappointment appeared on his face: "It turns out that no one can crack MD5. What a pity." He had no doubts about Biham's verification results.

Not only him, but many other cryptographers also stopped the verification step.

Although the collision method used in this paper to crack MD5 is very good and provides new ideas for studying hash functions, it is normal that the result is incorrect.

After all, it has troubled the entire cryptography community for more than ten years, so how could it be easy to crack?

Given Biham's identity and status in the cryptography community, what he says represents absolute authority. Since the verification results are already inaccurate, there is naturally no need for them to waste any more effort.

Soon an atmosphere of disappointment and frustration spread in the lecture hall.

Cracking the MD5 password can be said to be the lifelong dream of many cryptography experts. Today, they are very close to success, but in the end it still ends in regret, which inevitably makes everyone feel a deep sense of powerlessness and frustration.

It seems like no one can crack it.

However, there were people in the lecture hall who were in a completely different mood: an official from the Bureau of Standards and Technology.

Lehman's face was full of smiles at this time, and he proudly said to his subordinates beside him: "I have already said that it is impossible for anyone to crack the MD5 password."

"You are quite right, Mr. Lyman."

"The designer of MD5 is Professor Rivest. As a winner of the Turing Award, his research in cryptography and network security is unmatched by anyone else." The subordinate took over the conversation and answered proudly.

At this time, Professor Wang Xiaoyun could not help but come to the stage and said to Professor Biham: "Professor Biham, our results must be correct."

They had verified this long before officially writing the paper, and the results were completely correct.

It's impossible to come here and it's wrong.

Biham naturally had absolute confidence in himself, and after hearing this, he still insisted on his previous point of view.

I said respectfully: "Professor Wang, I understand your feelings. Although you failed to crack the MD5 password, the differential collision method you studied is of great significance to cryptography."

In his opinion, Xu Yuan was simply reporting on the stage, and the specific collision method should be studied by the female cryptographer in front of him.

After all, no one will pay attention to a student.

Regardless of whether the MD5 password is successfully cracked, this paper is worthy of being called the best paper of this conference. I believe that there will be more and more yellow-skinned experts and scholars in the cryptography community in the future.

Xu Yuan listened to the conversation between Wang Xiaoyun and Professor Biham.

He didn't care who researched the collision method. The most important thing at the moment was to convince Professor Biham that MD5 had been cracked.

The thought stayed here, and soon a solution came to his mind.

Then he invited Professor Biham again: "Professor Biham, why don't we do a field test together and recalculate it."

"This is just a meaningless waste of time." Professor Biham wanted to refuse, but suddenly changed his mind the next second and said: "Since you are so insistent, let's do a final test on the spot." After saying that, he walked to the podium without hesitation.

Next, Xu Yuan, Wang Xiaoyun and Biham turned on the computer together and calculated from the last step forward.

As time passed, the calculation proceeded rapidly.

However, from the first step to the last step, their results are always different.

Faced with such a result, Biham finally sighed and said to Wang Xiaoyun beside him: "Professor Wang, you have already seen that the MD5 result is indeed wrong." On the other hand, Xu Yuan said confidently: "Professor Biham, one of your initial values ​​is wrong."

As soon as he finished speaking, he gave a detailed explanation.

"Our initial value comes from Schneier's book Cryptography and Security: From Theory to Application. It's obviously not the value you just entered. Professor Biham might as well re-enter the correct initial value."

When Biham heard what Xu Yuan said, he immediately put his eyes close to the screen and carefully checked his calculation process.

Sure enough, he found that the initial value he entered was different from Xu Yuan's.

Realizing that there was most likely a verification error, he did not bother to respond and immediately re-entered the initial values ​​in the book as quickly as possible.

And put it into the program and run it.

Soon he got the same result as Xu Yuan.

"Wonderful."

He stared at the screen with wide eyes, his facial expression quickly replaced by surprise, and he kept repeating a word.

This state lasted for three or four seconds before he came to his senses, stretched out his hand and said sincerely: "Congratulations, you have successfully cracked the MD5 password algorithm."

Xu Yuan and Wang Xiaoyun looked at each other and smiled happily.

Ding Jian, Wang Changxin and Cui Li in the audience stood up and applauded and cheered.

As for the other cryptographers, they were a little overwhelmed by the sudden turn of events. They were stunned for a moment before they reacted and quickly continued with the previous calculation steps to verify. Their emotions were aroused again.

Because some people did not stop their verification just now, they all got the correct results at this time.

They were so excited that they didn't care about the order of the conference, and voices of surprise continued to ring out in the main lecture hall.

"The MD5 result is correct."

"Oh my god, MD5 has finally been cracked."

“This will be a new milestone in hash function research, and it’s hard to imagine it coming from a new team.”

“I’m glad I had the privilege to witness it.”

“It’s perfect.”

……

Then the whole audience stood up and gave a warm round of applause, congratulating the team that cracked the MD5 password with the highest etiquette in the cryptography community.

Professor Desmed, who had an injured arm, slapped his thighs frantically to express his happiness at the cracking of the MD5 password.

Only Lehman, the head of the Bureau of Standards and Technology, and his subordinates remained seated.

His face looked very ugly, and he still couldn't believe what was happening before his eyes.

“Have the verification results come out?”

"Tell me quickly that their MD5 result is wrong, our MD5 password algorithm has not been cracked, and why the final verification result has not come out yet."

Lehmann managed to remain calm, but he urged his subordinates around him almost hysterically. He didn't believe that the MD5 encryption algorithm they were so proud of would be cracked by others, especially by a research team he had never heard of.

Unfortunately, his voice was completely drowned out by the deafening applause and cheers.

The subordinates next to him never thought that Professor Biham, a world-class cryptography expert, would make a mistake in the initial value.

So now he had no choice but to continue the unfinished verification, typing quickly on the laptop keyboard with both hands, and was urged by his boss not to be negligent in any way.

Not long after.

The program runs to obtain the result.

When the image on the screen jumped into his eyes, his pupils couldn't help but shrink suddenly.

The expression was in disbelief.

"The MD5 result is completely correct. They really succeeded in cracking the MD5 cryptographic algorithm using the differential collision method."

He had just murmured these words in a lost and soul-stirring voice when Lehman snatched the laptop away and confirmed the results on the screen himself.

Although he was unwilling to believe that the MD5 password that the Bureau of Standards and Technology was so proud of would be cracked, when the cruel reality lay before him, he could not change anything.

The whole person remained in a stiff position for more than ten seconds, and then suddenly became like a deflated ball.

I lost strength in my hands and almost dropped my computer.

"Hold a press conference as soon as possible. MD5 is dead and needs to be phased out and replaced with a new cryptographic algorithm."

When the subordinate next to him heard Lehman's weak words, he quickly responded: "I understand, Mr. Lehman. I will arrange this matter now."

It can only be said that the National Institute of Standards and Technology responded very quickly. Almost on the same day, the official announced that it would replace the MD5 encryption algorithm. At the same time, the news that the MD5 encryption had been cracked spread like wildfire, and both the Times and the New York Times reported it accordingly.

(End of this chapter)