Questions tagged [hybrid-encryption]

Hybrid encryption combines secret-key and public-key cryptography into an encryption scheme.

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How is hybrid (RSA+DH) more secure than RSA quantitatively?

Is there any graph that serves as a comparative analysis for the factorization problem vs discrete logarithn problem? I am implementing an hybrid encryption algorithm (RSA + Diffie-Hellman) and it is ...
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Am I applying Hybrid lemma and proof by contradiction correctly?

In the following scenario, I am trying to apply proof by contradiction. My idea is to use a Hybrid lemma. So if I am able to distinguish $G'$, this implies we are able to distinguish $G$. But we ...
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In a hybrid cryptosystem is safe to send the encrypted key together with the encrypted message?

I am encrypting a message using an hybrid cryptosystem: I encrypt my message using AES-256 and I encrypt the symmetric cipher key using RSA. The following questions come to my mind: I want to know if ...
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How can Whatsapp identify forwarded attachments

Sometimes Whatsapp shows that an attachment was often forwarded. How do they know this if the message is end-to-end encrypted? Even with hybrid encryption I encrypt with my key and store my attachment ...
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what's the purpose of passphrase in hybrid cryptography?

What's the purpose of a passphrase in hybrid cryptography? can it actually be used for authentication or if i put in another signature algorithm will it be like, two authentications?
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Using xor encryption in the following use case

I use an encryption scheme based on a symmetric cipher, with the corresponding symmetric key encrypted with RSA/OAEP using the public RSA key of the recipient. I now want to use ECC crypto in ...
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Is there a term for cryptographic attacks where you can verify decryption without assuming any known structure on the plaintext?

The questions https://security.stackexchange.com/questions/1696/if-someone-breaks-encryption-how-do-they-know-theyre-successful and https://security.stackexchange.com/questions/119887/how-to-know-if-a-...
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Securely “forwarding” a Large message in a hybrid encryption system without sending the actual message

Alice has symmetrically encrypted the large (100Mb) MessageA with a random key K1, and then asymmetrically encrypted K1 with Bobs public key. She then stores the encrypted large message in a central ...
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Is Googles Envelope Encryption the same as Hybrid Encryption?

Google is advertising the use of Envelope Encryption in their products with their KMS. By the description, it sounds very much like Hybrid Encryption. But since I could not find any reference to ...
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Is hybrid encryption required to use Attribute based Encryption to encrypt messages?

Does the mechanism behind Attribute Based Encryption require us to first encrypt the message by using a symmetric cipher, e.g. AES, and then encrypt the AES key by using Attribute Based Encryption? ...
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Hybrid cryptosystem

I'm using RSA (4096) and AES GCM (256) to exchange messages between A and B. A random key for AES is generated, the plain message is encrypted with AES, and the random AES key is encrypted with Bs ...
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Make AES more secure by randomising the blocks in an encrypted file

I am developing a software with hybrid encryption (RSA-4096 and AES-256-CBC). The iv and key of an AES encrypted file will be RSA encrypted end exchanged through a different way than the encrypted ...
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Understanding hybrid cryptography's concepts: signing and CA

After learning about symmetric encryption, public-key encryption, one-way hash, digital signature and digital certificate, I was tasked to think of an imaginary hybrid cryptosystem. I was thinking ...
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Is Hybrid Encryption CCA secure?

If Enc is a PKE(Public Key Encryption) with key generation algorithm KG and message space $M = \{0, 1\}^n$, and SE is a Symmetric Key Encryption(SKE) with key space $\{0, 1\}^n$ and message space $M' =...
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A paper question about the security of hybrid encryption scheme

Why the decryptor can still use K to access the data even when K is updated? QAQ
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What is this called: encrypt $X$ with key $E$, decrypt $X$ with key $D$?

I am a software developer interested in developing an application with cryptography. I can explain what I want to accomplish, but I do not know the technical terms for the cryptographic functions I am ...
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Can I replace DH by a post-quantum key exchange in IBAKE for post-quantum identity-based authenticated key exchange?

IETF RFC 6539 IBAKE - Identity Based Authenticated Key Exchange describes a Hybrid key exchange using both Identity based cryptography and a standard ephemeral elliptic curve Diffie-Hellman key ...
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How many keys in a Hybrid Cryptosystem?

If symmetric cryptosystems have $C^2_n$ keys, and asymmetric systems have $2n$ keys, how many does a hybrid system have? This was in an online quiz from school Company A is considering to adopt ...
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Commitment scheme: hiding property

Given two commitment schemes $Com_1, Com_2$ (both have the hiding property), I'd like to prove $Com_1(m) || Com_2(m)$ is also hiding. I built these hybrids and want to show $H_0 =_c H_1 =_c H_2$. \...
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Newbie - Hybrid Symetric and Asymetric

Just looking for a bit of an explanation on the concept of hybrid symmetric and asymmetric encryption. My understanding: Client requests public key from https://site1.com The client receives the ...
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Given paramaters of an Edward's curve and x, determine a y value if it exists

I'm making a demonstration cryptosystem using ECC ElGamal. I've currently got a working implementation of Edward's Curve operations and a basic ElGamal implementation (Encrypts only points on the ...
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How to securely map messages to points on an elliptic curve

I'm implementing a demonstration hybrid cryptosystem in Python (FinCrypt, I know the name is bad) and I'm migrating over from my Weierstrass curve implementation, which was based off of this, to one ...
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Encrypting with Asymmetric keys

I'm designing a system where the client asked for documents to be encrypted with "asymmetric cryptography". I've explained them that the best practice is to encrypt the data with a symmetric ...
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When do I need to use hybrid cryptography?

I need to provide confidentiality for a protocol. The protocol message size is between 100 bytes to 500 bytes. Do I need to use asymmetric encryption or hybrid cryptography?
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Encrypt with elliptic curves [closed]

The last days I was looking for a way to encrypt using ECC, without having to make the program myself. I was sure that someone should have done it for everyone by now. The best approach I had was ...
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In cryptography is there such as thing as disguising unencrypted text?

Just wondered: I currently have TrueCrypt on my system (I am aware that there are various doubts about its penetrability, and that it is no longer under development). TC "volumes" obviously consist ...
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RSA hybrid decryption via PKCS#11 - unwrap or decrypt?

I have an application that does RSA hybrid encryption/decryption – i.e., messages are encrypted with a fresh AES key, which is then itself encrypted with RSA-OAEP and sent with the message. Decryption ...
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Using HKDF to derive symmetric keys from a hybrid public-key encryption scheme

RFC 5869 describes HMAC-based Extract-and-Expand Key Derivation Function (HKDF). In section 4, entitled "Applications of HKDF", it states that one of the intended uses is: derivation of ...
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Doing RSA-KEM with RSA-OAEP

I am fiddling around with the JS Web Crypto API and creating a hybrid encryption system that uses a symmetric key to encrypt form data with AES256-CBC and and a public/private key-pair to wrap/...
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Is a signature scheme using a hash considered a hybrid cryptosystem?

In Wikipedia there is a page on hybrid cryptosystems. However, although cryptography contains a lot more than just encryption, only hybrid encryption using key encapsulation and data encapsulation is ...
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minimal overhead of ChaCha20 + ECC

What we want? Encrypt plaintext with ChaCha20 + ECC on curve 25519 (hybrid cryptography) the result would be a data stracture X. Input: public key on Curve 25519 No authentication required (no AEAD)...
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Can I overcome ElGamal malleability with AES preprocessing?

So textbook ElGamal is known to be vulnerable to CPA, and although there are several proposals (DHAES/EIES) for modifications none of those are formally accepted or standardized. My question is ...
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What is the “correct” way to authenticate hybrid encryption?

In hybrid encryption we use an asymmetric encryption scheme and the recipients public key to encrypt a symmetric encryption key $K$. I will denote the resulting ciphertext $C_A$. We then use a ...
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Would reuse of the symmetric key in a hybrid cryptosystem between files be inherently insecure?

This question stems from a UX problem where I want to allow the user to input their PIN only one single time when they open up an mobile app. Here are some properties of the application to provide ...
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How to do statistical analysis on encrypted / anonimized data

Let's imagine Alice wants to send Bob a table with 2 columns: ...
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Why is RSA still being used? [duplicate]

In hybrid encrytion, I still see that some site's use RSA in their https connection, so now I wonder, why do they not use ECC instead of RSA, ECC requires less computational power and encrypt's and ...
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Why is hybrid encryption more effective than other encryption scheme?

Currently I am learning about Hybrid Encryption but I was not able to find any good study material. Below is my understanding: One of the reason why we use ...
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Symmetric encryption using RSA for random generated password

I'm fairly new to encryption, so I wanted to check the logic for a .net solution I'm working on that encrypts data between two parties. the receiving (decrypting) party will have an RSA key pair ...
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Multi-party encryption algorithm

To give some foreground information: I acknowledge that I am a cryptography newb and not by any means an expert (and probably never will be). In a recent CS class we had several assignments writing ...
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hybrid PKE scheme CCA2 insecurity

I'm reading "An Efficient CCA2-Secure Variant of the McEliece Cryptosystem in the standard model" by Rastaghi which states: As we know, in hybrid PKE schemes XOR alone cannot perfectly hide ...