Questions tagged [decryption]
In cryptography, encryption is the process of encoding information. This process converts the original representation of the information, known as plaintext, into an alternative form known as ciphertext. Only authorized parties can decipher a ciphertext back to plaintext and access the original information.
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Is direct RSA encryption of AES keys secure?
I am wondering: If we take this scheme/procedure and each of it seems very secure (to me at least), is it truly secure or is there a vulnerability hidden in the process?
This is the scheme:
Bob has ...
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How are side-channel attacks executed? What does an attacker need to execute a side channel attack?
I've been reading about side-channel attacks on Wikipedia, and it seems that some of these can only be executed on the victim's computer. (I am specifically asking about the side-channel attacks ...
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Advantages and possible usages of encryption schemes with probabilistic decryption
We can define deterministic and probabilistic encryption;
Deterministic $c = E(k,m)$, and
Examples are textbook RSA, block ciphers in ECB mode.
Deterministic encryption fails to achieve CPA security....
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Is multiple encryption using a block cipher mode of operation that use only encryption processes vulnerable to Meet-in-the-middle attacks?
Some block cipher modes of operation use only encryption processes, such as CFB, OFB and CTR.
If doing multiple encryptions using them, will these encipherment schemes be vulnerable to Meet-in-the-...
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How can I reverse a so-called CRC16 from the data?
I am trying to understand a request I reverse engineered which is sent to a Daly BMS over BLE.
Those requests change the 'sleep after' in seconds of the BMS:
For DDDD seconds: ...
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Am I Doing RSA Correctly?
I am trying to figure out how to complete RSA manually. I am trying to encode a simple block message (Mi). I used CrypTool to determine the encryption. When I "manually" computed the ...
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Special characters in AES Encryption Key
We all know that AES uses Key, IV and salt. But what if we add special ASCII characters like Alternate 255 (" ") or Alternatively 163 ("£") or Alternate 224 ("α") in the ...
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How long does it take to crack RSA 1024 with a PC?
Using an Intel Core i5 CPU, how long does it take to crack RSA using a key size of 1024 bit (generated using a secure key pair generation function)?
Suppose for instance that we have thousands of ...
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Cryptography elements needed for a story
Note: following Maarten Bodewes's answer, I edited this post to make it clearer.
I'm writing something partly driven by the need to crack a few encrypted files.
This is what needs to happen in the ...
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"hex" vs. "base64" encoding when enciphering
Examining different implementations of encryption / decryption with cipher on Node.js, I paid attention that some implementations use hex encoding:
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How to share decryption ability to others whose public keys are not used during encryption?
as the title says, for example, A uses B's public key to encrypt a message and sent it to B. In later stages, a new member C joins and B would like to let C be able to see this encrypted message (i.e.,...
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Are there any cryptographic algorithms, which lets the user apply some modifications on the encoded data, without decoding it?
I would like to encode some data with a key, and send it to a third party. They don't know the key to decode it, but I would like to make it possible for them to apply some modifications on it. Then ...
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value bound of r⋅e for LWE Decryption correctness
For LWE decryption, Someone told me that If we can bound r⋅e by q/4 then we can retrieve M by checking if this is closer to <...
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My RSA decryption doesnt match answer
Break the RSA code whose key is $(n, e) = (8369428283, 1234567)$.
Find the deciphering key and then decipher the message under the assumption that the plaintext consists of 7-letter blocks in the ...
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How to decrypt Rabin message when p=q and you have the roots from Tonelli-Shanks
I've been trying to decrypt a message encrypted with Rabin as a challenge. I'm very new to cryptography and these challenges so much of this is new.
I've factorised n and determined that p=q which I ...
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Implementing AES GCM but not getting correct output from cipher block
I'm implementing 128-bit AES-GCM (but only the encryption/AES-CTR aspect).
When I set the Secret Key, Plaintext and IV to Test Case 2, page 27 of the GCM spec (see below) I get the wrong value for the ...
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From Entropy's perspective how Encryption affects a Message?
How Ciphers, specifically, Substitution Ciphers and Transposition Ciphers manipulate the Entropy of Plaintext w/wo the aid of Entropy Source?
Reversely, how Decryption manipulates the entropy of ...
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Are asymmetric encryption and decryption same function? [closed]
In asymmetric key encryption, we have 2 functions, encrypt(m,k) and decrypt(m,k), and 2 keys, ...
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Number of operations for Elgamal cryptosystem
In page 408 of Hoffstein, Piper, and Silverman's Introduction to Mathematical Cryptography, it says
"Roughly speaking, in order to achieve $k$ bits of security,
encryption and decryption for ...
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A doubt about Diffie-Hellman Key Exchange
I have a doubt about the Diffie-Hellman problem:
Is it possible to send a message to someone using only the Diffie–Hellman key exchange?
Since it's called a key exchange can you only make a key?
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