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Does Man-In-Middle attack isn't possible when we use reverse of RSA algorithm in Digital signature?

Yes, anybody can perform modular exponentiation using the public key. This would then result in a padded hash, which would in turn contain the hash. So if an adversary is able to guess the input data ...
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E382 and E521 edward curves test vector

E382 and E521 are just curves, just like Ed448-Goldilocks is just a curve. To implement a signature scheme, design decisions need to be made. For example, "Ed448" is the name given to a ...
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1 vote

Isn't an asymmetric cipher (like RSA) algorithm sufficient for all basic needs, when speed is irrelevant?

For the same key sizes, symmetric encryption protocols are safer than asymmetric protocols. Informally, the cryptanalysis algorithms used to decipher RSA try to identify the prime values used to ...
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2 votes

Isn't an asymmetric cipher (like RSA) algorithm sufficient for all basic needs, when speed is irrelevant?

Beware that beside RSA, we don't know many "asymmetric block ciphers" per the question's definition (essentially trapdoor permutations), thus building over this won't allow substitution with ...
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1 vote
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Classical vs Quantum-Safe Algorithms and Protocols / Application Approach

Various proposals are being explored for X509 V3 certificates in a Post Quantum Cryptography (PQC) world. Is this understanding, correct? In my view, there are essentially two way to have both ...
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2 votes

Performance comparison between ECDSA and BLS signature schemes

In fact it depends on various factors: Which curves and which level of security is your target? Which algorithms do you most frequently use key generation, signing, or verification? Which ...
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1 vote

Performance comparison between ECDSA and BLS signature schemes

Found this article that seems to answer your question: https://www.dash.org/blog/bls-is-it-really-that-slow/
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How does the KeyGen of Merkle's improvement of Lamport's OTS work?

You only need to store the hash values for the 1s. The checksum bits at the end (which encode the number of 0s) ensure that messages cannot be crafted in such a way to flip 1s down to 0s as doing so ...
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2 votes

Why don't crypto-currencies use the Lamport signature scheme?

The Capitalisk (https://capitalisk.com/) blockchain uses the Lamport OTS Scheme in conjunction with the Merkle Signature Scheme (MSS) to produce signatures. MSS provides some degree of key reuse which ...
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2 votes
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Digital signature forgery

TLDR: the attack considered is not easy. It's possible, or not, depending on unstated hypothesis. First we'll rephrase the question¹. We assume an asymmetric encryption system, similar to textbook ...
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1 vote

Proving you're from the year 2069

This can be done using the RFC 3161 standard, for example. There are similarities with your idea, using a PKI and digital signatures. The keyword is Trusted Timestamping and it requires a trusted ...
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3 votes
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Lamport Diffie One-time Signature

I am going through the Lamport Diffie One-time signature. As a side note; this work is an early effort that culminated in what is known as "Stateful Hash Based Signature Methods"; modern ...
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0 votes

Digital signature forgery

Generally, no. First of all, it should be noted that most digital signatures cannot be thought of as hash, then encrypt with a private key. Encryption cannot be performed with a private key as anybody ...
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2 votes

Is it safe to sign message with a TLS private key?

You could sign the files using the server TLS private key for sure. Then on the client side, you could retrieve the TLS certificate used for the HTTPS link using some code e.g. with OpenSSL as I wrote ...
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1 vote

Is it safe to sign message with a TLS private key?

The term tls private key is ambiguous. The PRF generates from the negotiated premaster secret a whole bunch of different keys depending on the selected cipher suite. May be you mean the private key ...
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