Linked Questions
44 questions linked to/from Should we sign-then-encrypt, or encrypt-then-sign?
2
votes
3
answers
233
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Is PGP's way of maintaining email security optimal? [duplicate]
I read a book called "computer networking: A top-down approach". It talked about how PGP creates an email message between Alice and Bob to maintain confidentiality, integrity, and authenticity. Let me ...
0
votes
0
answers
58
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Importance of the order of public/private key application to a signed encrypted message [duplicate]
Let's say two users (U1, U2) each have a private key they keep to themselves, and each broadcast a corresponding public key to the world.
Let's then say that U1 wants to send a signed encrypted ...
0
votes
0
answers
50
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Should I encrypt the signature along with the message? [duplicate]
Given that A wants to send a message M to B,
I have 2 scenarios as shown:
The difference between the 2 is that for case 1, the digital signature is appended to the message before being encrypted ...
0
votes
0
answers
46
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Is sending encrypted message and signed message a secure way of transmitting data? [duplicate]
I know that the industrial standard is normally sending data in the following format:
Send Encr(msg, Sign(msg))
Is the following way a secure as well?
...
423
votes
13
answers
190k
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Should we MAC-then-encrypt or encrypt-then-MAC?
Most of the time, when some data must be encrypted, it must also be protected with a MAC, because encryption protects only against passive attackers. There are some nifty encryption modes which ...
7
votes
6
answers
2k
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Is there an authenticated encryption scheme where the recipient can attribute the message to a single sender?
With a standard authenticated encryption scheme (or MAC), Alice and Bob share a symmetric key. When Alice sends something to Bob, Bob can check that it is authentic. At that point, Bob can deduce ...
9
votes
2
answers
11k
views
How to verify the integrity of RSA encrypted messages?
I need to encrypt messages using PublicKeyCrypto and send it to the server, where the message should be decrypted. I'm aware of the Padding Oracle Attack and want to apply a server side integrity ...
13
votes
1
answer
5k
views
Why do we encrypt-then-mac but sign-then-encrypt?
This question was asked in comments on my answer to Should we MAC-then-encrypt or encrypt-then-MAC? I think posing the question as a separate entity is best, so:
The general advice for applying MACs ...
5
votes
1
answer
4k
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Do I need to use a MAC with asymmetric encryption?
The internet has drilled into me that when I delivery any symmetrically encrypted data, I should also deliver a MAC to authenticate it before any decryption occurs. Do I also need to do this if I use ...
2
votes
1
answer
4k
views
Will publishing two or more public keys of the same RSA private key cause a security risk?
I want to make an end-to-end messaging platform where everyone is identified with a unique random private key. Everyone uses other peers' public keys to identify and send encrypted messages and verify ...
5
votes
2
answers
1k
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What is the best way to sign a message using RSA?
I was preparing for competitive exam, and I came across this question. I had a lot of discussion with my friends before I resorted to posting it here and I wanted myself to be clear on this.
Let $M$ ...
2
votes
3
answers
1k
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Benefits of signing RSA-encrypted data?
I recently came across this (PDF) journal article, which describes what it calls "A New Design Of A Hybrid Encryption Algorithm" (which I must say, doesn't sound very novel, even in 2014!):
An AES ...
6
votes
2
answers
1k
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Why does Encrypt-Then-Sign not yield a CCA-secure public-key encryption scheme?
In symmetric cryptography, combining an IND-CPA secure symmetric encryption scheme with a secure MAC with the encrypt-then-MAC method yields a IND-CCA secure symmetric encryption scheme.
I am trying ...
4
votes
2
answers
926
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ECIES with ECDSA
I understand how ECIES work. I have a structure of message
[alice`s ephemeral public key, MAC tag, ciphertext]
I do not understand what I shoud do if I want to ...
3
votes
2
answers
690
views
Does it make any sense to sign a GCM authentication tag with RSA?
To achieve double insurance for authentication, can we sign the GCM final tag with using RSA?
with RSA, no one is able to create his own tag since the private key is not known.
However, according to ...