Arcitura Education S90.18 Exam - Topic 4 Question 114 Discussion

Actual exam question for Arcitura Education's S90.18 exam

Question #: 114
Topic #: 4

Service A hashes a message, resulting in message digest X. Service A encrypts message digest X with its private key, resulting in cipher text X1. Service A sends the message and X1 to Service B. Service B hashes the message, resulting in message digest Y. Service B decrypts X1 with Service A's public key, recovering message digest X1. Service B compares X and Y and finds them not to be equal. This proves that;

Athe message was altered

Bonly Service A sent this particular message

Cpublic key cryptography was used

DAll of the above

Show Suggested Answer

Suggested Answer: D

by Izetta at Jul 10, 2025, 07:30 PM

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Lemuel

4 months ago

All of the above sounds right to me!

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Geoffrey

4 months ago

Public key cryptography was definitely used here.

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Brett

4 months ago

The message was definitely altered.

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Dulce

5 months ago

Wait, how can we be sure the message was altered?

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Elenore

5 months ago

I agree, that's the only conclusion.

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Shaquana

5 months ago

I think all of the options could be true in this context, especially since the message digest comparison is a key part of verifying integrity.

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Margurite

5 months ago

I feel like the fact that Service B decrypted with the public key is important, but I can't recall if that alone proves anything about the message being altered.

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Arthur

5 months ago

This scenario seems similar to a practice question we did about digital signatures. I think if the digests don’t match, it indicates tampering.

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Edward

6 months ago

I remember studying how hashing and encryption work together, but I'm not entirely sure if the comparison of digests directly proves the message was altered.

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Avery

6 months ago

Alright, let me break this down. The fact that the message digests don't match means the message was altered. I've got this!

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Lavonna

6 months ago

This looks like a classic cryptography question. I'm feeling pretty confident I can work through this step-by-step.

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Ernest

6 months ago

I'm a bit confused about the role of the public and private keys here. I'll need to review that part of the material again.

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Elmira

6 months ago

Okay, I think I've got this. The key is to focus on the comparison of the message digests and what that implies.

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Laila

6 months ago

Hmm, this seems like a tricky one. I'll need to carefully think through the steps to make sure I understand what's happening.

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Ngoc

8 months ago

I wonder if Service A and Service B are on speaking terms after this little mix-up. Maybe they need to have a 'hash it out' session.

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Reita

8 months ago

I think the answer is D) All of the above, as it covers all possibilities.

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Annett

8 months ago

I agree with Joaquin, C) public key cryptography makes more sense.

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Robt

8 months ago

This is a tricky one, but I'll go with D. All of the above. The differences in the message digests indicate the message was altered, and the use of public key cryptography is evident.

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Wai

7 months ago

I think D is the right answer too. The mismatch in the message digests shows the message was tampered with.

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Margot

8 months ago

I agree, D seems like the correct choice. The message was altered and public key cryptography was used.

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Janessa

9 months ago

I'm going with B. Only Service A sent this particular message. The decryption of the cipher text with Service A's public key confirms the sender's identity.

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Galen

9 months ago

Definitely D. The fact that the message digests don't match proves the message was altered, and the use of public key cryptography is a clear giveaway.

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Hillary

8 months ago

User 2: Agreed. It's a clever way to ensure the integrity and authenticity of the message.

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Paris

8 months ago

User 1: Definitely D. The fact that the message digests don't match proves the message was altered, and the use of public key cryptography is a clear giveaway.

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