<p>"Quantum Computers" may give you significant speedup in many types of attacks.
These speedups may not necessarily be exponential like the current Shor's algorithm usage for breaking RSA.
You may find more information here: <a href="https://security.stackexchange.com/questions/116596/will-quantum-computers-render-aes-obsolete">https://security.stackexchange.com/questions/116596/will-quantum-computers-render-aes-obsolete</a> </p>

CC BY-SA 4.0
2018-06-29T20:19:13.110Z
2018-06-30T10:40:24.107Z
2018-06-30T10:40:24.107Z
Avi Tal
<p>There was just a paper published by R3 on a cryptographic method using Merkle trees adapted for blockchain (<a href="https://eprint.iacr.org/2018/658.pdf" rel="nofollow noreferrer">https://eprint.iacr.org/2018/658.pdf</a>). The field of PQ-Cryptography is right now reliant mainly on hashes and other algorithms that are not dependent on the factoring problem (or modifications of this problem such as the discrete log). Altered Bulletproofs and Ring Signatures are two current post-quantum secure algorithms that show promise (NTRU in particular). I advise you submit this post on (<a href="https://crypto.stackexchange.com/">https://crypto.stackexchange.com/</a>) as that is an SE for cryptography.</p>

CC BY-SA 4.0
2018-07-30T12:14:18.953Z
2018-07-30T12:14:18.953Z
John Miller
<p>Are there any cryptosystems that we know that would be secure against an attack by a quantum computer?</p>

<p>Are there problems which are known or suspected to be hard for quantum computers, and can these be utilized to yield cryptographic protocols which are secure against quantum computers?</p>

CC BY-SA 4.0
2018-06-29T05:02:37.667Z
The key search term for that literature is “post-quantum cryptography”.
Abel Molina
CC BY-SA 4.0
2018-06-30T19:24:39.093Z
Intuitively, the protocols that utilize problems not in $\mathrm{BQP}$... (I do not know too much about either crypto or complexity theory, though)
xrq
CC BY-SA 4.0
2018-07-31T13:30:23.340Z
I am no expert, but I think lattice cryptography, like schemes based on the Learning with Errors problem, are conjectured to be secure against quantum attacks. This would follow from worst-case quantum hardness of variants of the shortest vector problem.
Sasho Nikolov
CC BY-SA 4.0
2019-09-11T07:21:35.233Z
Note that Cryptography protocols and [Cryptosystems](https://en.wikipedia.org/wiki/Cryptosystem) are not the same.
kelalaka
<quantum-computing><cr.crypto-security>
Which cryptographic protocols are secure against quantum computer attacks?
Karagounis Z
# Which cryptographic protocols are secure against quantum computer attacks?

(Asked by: username_0 on 2018-06-29)

Are there any cryptosystems that we know that would be secure against an attack by a quantum computer?

Are there problems which are known or suspected to be hard for quantum computers, and can these be utilized to yield cryptographic protocols which are secure against quantum computers?

**Tags:** quantum-computing, cr.crypto-security

> **Comments:**
> **username_1**: The key search term for that literature is “post-quantum cryptography”.  
> **username_2**: Intuitively, the protocols that utilize problems not in $\mathrm{BQP}$... (I do not know too much about either crypto or complexity theory, though)  
> **username_3**: I am no expert, but I think lattice cryptography, like schemes based on the Learning with Errors problem, are conjectured to be secure against quantum attacks. This would follow from worst-case quantum hardness of variants of the shortest vector problem.  
> **username_4**: Note that Cryptography protocols and [Cryptosystems](https://en.wikipedia.org/wiki/Cryptosystem) are not the same.  

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## 2 answers

### Answer by username_5 on 2018-06-29. Score: 1

"Quantum Computers" may give you significant speedup in many types of attacks.
These speedups may not necessarily be exponential like the current Shor's algorithm usage for breaking RSA.
You may find more information here: <https://security.stackexchange.com/questions/116596/will-quantum-computers-render-aes-obsolete>


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### Answer by username_6 on 2018-07-30. Score: 0

There was just a paper published by R3 on a cryptographic method using Merkle trees adapted for blockchain (<https://eprint.iacr.org/2018/658.pdf>). The field of PQ-Cryptography is right now reliant mainly on hashes and other algorithms that are not dependent on the factoring problem (or modifications of this problem such as the discrete log). Altered Bulletproofs and Ring Signatures are two current post-quantum secure algorithms that show promise (NTRU in particular). I advise you submit this post on (<https://crypto.stackexchange.com/>) as that is an SE for cryptography.


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