Category Archives: RSA

Improving Shor’s Algorithm

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We don’t have a useful quantum computer yet, but we do have quantum algorithms. Shor’s algorithm has the potential to factor large numbers faster than otherwise possible, which—if the run times are actually feasible—could break both the RSA and Diffie-Hellman public-key algorithms.

Now, computer scientist Oded Regev has a significant speed-up to Shor’s algorithm, at the cost of more storage.

Details are in this article. Here’s the result:

The improvement was profound. The number of elementary logical steps in the quantum part of Regev’s algorithm is proportional to …

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In RFC 2313 (PKCS1/RSA) said you could recreate the Private key from ‘n’ and ‘d’, which later versions removed. Why? [migrated]

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RFC 2313 has this specific callout:
1. An RSA private key logically consists of only the
modulus n and the private exponent d. The presence of the
values p, q, d mod (p-1), d mod (p-1), and q-1 mod p is
int… Continue reading In RFC 2313 (PKCS1/RSA) said you could recreate the Private key from ‘n’ and ‘d’, which later versions removed. Why? [migrated]→

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Why in "openssl pkeyutl -verify" is needed both public and private keys? Why isn’t public key enough?

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I created a signature with:
openssl pkeyutl -sign -inkey rsa.key.bob -in plain -out plain.sig.bob

and to verify, Alice just needs to use Bob public key to check the authenticity of the message.
So why I have to use this (which require th… Continue reading Why in "openssl pkeyutl -verify" is needed both public and private keys? Why isn’t public key enough?→