Original Message:

Sent: Fri April 14, 2023 02:26 AM

From: Diego Cardalliaguet

Subject: How many Number of qubits required for decryption

Hi,

you'll need a calculation in a case-by-case basis. There's no general rule.

For RSA2048 you need 20 million qubits and 8 hours.

https://cacm.acm.org/news/237303-how-quantum-computer-could-break-2048-bit-rsa-encryption-in-8-hours/fulltext

If you search, you'll see that there are some variations depeding on the technique used.

Regards,

D.

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Diego Cardalliaguet

Europe, Middle East and Africa GEO Technical Sales

IBM

Original Message:

Sent: Fri April 14, 2023 12:49 AM

From: Ken Iida

Subject: How many Number of qubits required for decryption

How many qubits are enough qubits? I want to know that.

I'm not planning on doing anything bad. As a person entrusted with system operation by a customer, I think it is necessary to have a quantitative knowledge of the threats that are likely to occur in the future.

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Ken Iida

Ken.Iida@kyndryl.com

NagoyaJapan

Original Message:

Sent: Thu April 13, 2023 08:29 AM

From: john Marshal

Subject: How many Number of qubits required for decryption

The number of qubits required for decryption depends on the strength of the encryption algorithm used and the specific type of encryption being used. In general, most modern encryption algorithms are designed to be very difficult to crack using brute force methods, even with a quantum computer.

One of the most commonly used encryption algorithms is the Advanced Encryption Standard (AES), which is widely used in applications such as online banking and secure communications. AES-128, which uses a 128-bit key, is currently considered to be very secure against brute-force attacks using classical computers. However, it is theoretically possible that a quantum computer with enough qubits could break AES-128 encryption much more quickly than a classical computer.

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john Marshal

Original Message:

Sent: Wed April 12, 2023 12:17 AM

From: Ken Iida

Subject: How many Number of qubits required for decryption

There are RSA, DES, AES, etc. in the ciphers currently in widespread use in the world.

How many qubits would be needed to crack these ciphers using a quantum computer?

For example, how many qubits would it take to decrypt 1024-bit RSA?

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Ken Iida

Ken.Iida@kyndryl.com

NagoyaJapan

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