Questions tagged [integrity]
In a cryptographic sense, integrity means unimpaired and complete.
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Answering boolean question without knowing "Who" answer [closed]
Can cryptography solve this problem?
Two people are chatting, Mr. X and Ms Y. They give each other a CRC16 hash of someone's name initials and salt a random number at the end (suffix).
Ms Y: "I ...
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DTLS 1.2 Cipher Suites With AES-GCM – What data (if any) is passed to the AES-GCM cipher as the Additional Authentication Data?
It is DTLS 1.2 version question of this question.
I know from 4.1.2.4. of RFC 5246 (DTLS 1.2) AEAD Ciphers can be used in DTLS 1.2 exactly the same with TLS 1.2.
In TLS 1.2
AAD = seq_num + ...
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Does the order of validations and MAC with clear text matter?
I have a request in which I get a series of data in clear (nothing encrypted) and a MAC / authentication tag.
The question is whether the MAC should be validated first or if the fields are filled in ...
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Does the private blockchain have to follow client-server model when considering BFT?
I'm a newbie, currently interested in data security & integrity.
I'm quite new to blockchain and distributed system theories, and suffering from some unclear doubts/questions on the fault-tolerant ...
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Security proof of the Schnorr Signature
How Schnorr signature security can be proved for signature forgery, replacement, and Replay attacks?
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How do Pre-image, Second pre-image and collision resistance actually work? How does this affect data integrity?
I'm working on this past exam paper and found this question about pre-image resistance and its relation to data integrity:
Displaying the hash of a file on a website in order to provide data integrity ...
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How can you prove that a certain file was downloaded from a certain website?
Let's say you downloaded a file from a certain website, and later the website claims that it didn't made that file available, is there any way to prove that the website is lying?
Example 1: You ...
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What does AES-GCM provide?
I am wondering does AES-GCM which uses Authenticated Encryption provide us with all 3 properties (Authenticity, Confidentiality, and Integrity), or does it not provide integrity?
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Hash Function Vs Signature Vs MAC?
I read: What are the differences between a digital signature, a MAC and a hash?
and Found this amazing answer: https://crypto.stackexchange.com/a/5647
But one question remains:
I know that for huge ...
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Trustless deterministic fingerprint of additive subgroup of $GF(2^n)$
Suppose I have $k$ blocks $B_i$ each consisting of $n$ bits. For erasure code purposes I'd like to be able to produce a computationally binding deterministic hash/fingerprint/digest $H$ such that $\...
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Get Pixel Data from JPG/JPEG but still bring the integrity? [closed]
As far as I know, JPG is a lossy image compression format
Meanwhile, BMP is a generally uncompressed image format, whose file structure consists of bitmapFileHeader (14 bytes) and bitmapInfoHeader (40 ...
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Has reducing MAC size and increasing message size the same effect on security?
I am evaluating ways to reduce the overhead of (H)MACs on small messages. I was primarily wondering if there is a difference between halving the MAC length or keeping the same MAC length but using it ...
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Does CMS AuthEnvelopedData type provide message authentication?
I was looking through the S/MIME Message specification (RFC 8551) to find out what security services it offers. Section 2.4.4 of this document describing AuthEnvelopedData content type (which uses the ...
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Does SSL connection provide integrity?
I'm new to cryptography and I'm trying to implement a secure chat application using OpenSSL.
I want to ensure that public messages (which will be shown to all users) cannot be altered during ...
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Quantum secure algorithms
I want to know if the below algorithm , secure against quantum computing attack, and how I can compute the running time for the original algorithm and the proposed attack
Source: Yan Zhu, HuaiXi Wang,...
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Prove that secure authenticated encryption system composed with itself is secure
Suppose $(E,D)$ provides authenticated encryption with key space $K$. Define $(E',D')$ with key space $K^2$ as follows:
$$
E'((k_1,k_2),m) = E(k_2,E(k_1,m)) \\
D'((k_1,k_2),c) = \begin{cases}
D(k_1,E(...
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Is there a way to sign a message so that any subset can be verified?
I would like to know if there's a scheme that can allow something like the following:
Alice signs a message $M$ with signature $S$ and gives it to Bob and Mallory.
Bob can present any subset of $M$, ...
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Can ChaCha20 provide integrity?
I have read that in general stream ciphers do not provide data integrity. Can ChaCha20 be implemented in such a way (perhaps like counter mode with message authentication in AES) to provide this?
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getting key $k_{2}$ somehow definitely compromise authentication scheme and attacker can see cipher text now...so not secure
I was going through this question of nested encryption:
Given $\Pi$ = $({Gen}, {Enc}, {Dec})$ is authentication encryption we have designed new scheme $\Pi^{'}$ = $({Gen^{'}}, {Enc{'}}, {Dec{'}})$ ...
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Is the tag in a MAC scheme a fixed size?
I've been reading up on MAC schemes. But I cannot seem to find out whether the tag's that are output by running MAC(m) is of a fixed size?
I can find a lot of stuff talking about the tag space being a ...
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Is Poly1305 enough for cascading ciphers? [duplicate]
ChaCha20 along with Poly1305 provides confidentiality and integrity. Now suppose I cascade AES on top of ChaCha20. Is it safe to assume that the Poly1305 MAC is still secure, even if I cascade ...
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How can JWE support an integrity check given that it uses a public key to encrypt the message?
As far as I know JWE (JSON Web Encryption) supports both integrity and confidentiality. I agree about the confedintiality because only the recepient with a private key can decrypt a message. What ...
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What security guarantees do blockchains provide for data storage?
When it's considered, like here
a project where a user needs to store a (small piece of data) on a blockchain
what does that really mean from a cryptographer's perspective? What security guarantees ...
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MAC forgery using the DES's Complementary Property
I've started reading on MACs and working on a problem where given a MAC construction as $H_0=IV$ and for every $i>0$ $H_i=H_{i−1} \oplus E_{M[i]}(H_{i−1})$ and the tag is $(IV,E_{k_1}(H_ℓ))$, I ...
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OpenSSL FIPS integrity check
As far as I know, FIPS requires a set of self tests (POST) to verify the cryptographic algorithms permitted and the integrity of the module.
These tests are performed at run-time, so OpenSSL does a ...
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Provable Data Possession
While Provable Data Possession seems to be a very useful and interesting tool for ensuring integrity of data outsourced into Cloud providers, I have never seen a reputed Cloud provider talk about this ...
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Integrity for mixture of encrypted/unencrypted database fields
I have multiple blobs each (symmetrically) encrypted with its own randomly generated key.
Now I want to encrypt these blob keys with user keys and store them in a database.
A table could have the ...
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Is MAC process different for symmetric and asymmetric?
Message Authentication Code as far as I know works on the shared secret key. Do they work in the same way. Is there no difference between symmetric and asymmetric processes. Can anyone please explain ...
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If I want Integrity and Authentication AND Non-Repudiation, can the Digital Signature be based on the MAC?
Let's say I'm making a digital signature like this:
hash = hash(message)
digital signature = encrypt_with_private_key(hash)
where the private key is Alice's ...
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Boolean XOR function a valid way to verify the integrity of a message
Does the Boolean XOR function represent a valid way to verify the integrity of a message ?
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Using cryptography to protect database integrity
I'm designing a micro-services system where each service manages some set of entities (User, Account, e.g).
I want to be able to verify the authenticity of entity identifiers (e.g User-Id and Account-...
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How do AES and DES ensure data integrity?
I have been trying to study for cryptographic symmetric algorithms (AES,DES) and came up with a question whether these two on their own ensure integrity (i.e data has not been altered). Do these two ...
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Can a MAC be used as a HMAC?
I am reading through an information security book right now, and a confusing question poses itself to me:
"Could you use a MAC as a HMAC? That is, does a MAC satisfy the same properties that a ...
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Integrity of format preserving Encryption
In this question regarding integrity of FPE, the main point of the answer is that:
FFX is not malleable. [...] FFX can provide integrity protection in very limited circumstances.
So I was ...
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Information security evaluation
I saw this exercise for evaluating the security(confidentiality, integrity, authenticity, and non-repudiation) of some schemes:
ENC(M) || SignA(ENC(M))
...
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SHA-3 for Integrity
We used to use CRCs to check the integrity of files. For safety analysis we could associate a probability for detecting a corrupted bit in a large file. Now we are using an RSA Signed SHA-3 hash for ...
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Keeping a backup of asymmetric keys with the help of a certificate authority without losing the privacy
First I'll explain the problem, then I will also give a solution(it might be wrong) I've found for it, you let me know what you think about this solution and whether you have a better one.
Assume a ...
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Does stronger cryptographic hashes also imply being better at verifying integrity?
What I know so far
Fact 1) I know that all cryptographic hash functions have the following properties
They are many-to-one in nature
They produce fixed size outputs
Given an output ...
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AES, is this method to say "The password you entered is wrong" secure?
(TL;DR at the end)
Let's say the plaintext hello is encrypted with AES (CFB mode). I noticed that decryption works no matter the given password! Of course if the ...
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Best method for checking integrity of 50 GiB files?
I'm making backups of compressed data (using ZPAQ), some compressed archives are large (50 GiB)
I was just going to use sha3sum -a 512, for example:
...
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How reassuring is CRC-then-XTS as authenticated encryption?
It is known that the "xz" compression format embeds a checksum in the compressed file to verify integrity during decompression or standalone testing. The algorithm of the checksum can be one of: CRC32,...
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How to validate the authenticity and integrity of an XML document?
I am working on a C++ desktop application that reads an XML (also created by my org) from a public server (does not require authentication). I would like to make sure that the downloaded XML has not ...
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How are AEAD, GCM, CBC, Poly1305, EtM, MtE and E&M related?
I am using OpenSSL 1.1.1 to implement a TLS 1.3 communication module so I tried to learn how data integrity and authentication is ensured. I read a lot about AEAD, GCM, CBC, Poly1305, EtM, MtE and E&...
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Ensure Data Integrity In An ECDH Key Excange
Been playing around with the inner workings of onion routing and I have a problem. If I wanted to send the 2nd node of a relay network an ephemeral ECC public key, it has to go through node 1, so that ...
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SHA256 creates a unique hash for two *.wim that have identical content - are there better methods for verifying *.wim contents? [closed]
I'm trying to verify that the contents of a Windows Image are identical for two WIM files; however, I think the timestamps for the file modifications are affecting the final checksums--even though the ...
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Robust authentication and integrity for short OTP message
Using any of the wonders of modern cryptographic technology, how is it possible to package a tweet-sized plaintext, which is to be encrypted with a proper one-time pad, to ensure its integrity and ...
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Encrypting more than ~64GiB with AES-GCM - Integrity
I'm looking for solution to encrypt more than acceptable limit ~64GiB under same key with AES-GCM. I know I'm obligated to exchange nonces for each next ~64GiB chunk, but there is one thing that is ...
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Does it matter if I publish only publish good or bad MD5 hashes after recovering from a hack?
(This question is a follow-up from another question I asked about MD5, which is why I'm insisting on using MD5 in this question as well)
My imaginary Linux distribution, Sushi Linux has had a big ...
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Strategies for fast integrity attestation over multi party computation for large messages
I am looking for ways to efficiently perform integrity attestation over large messages using multi party computation. While, hashing (SHA1, 256...) is one alternative but it's painfully slow and grows ...
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Authenticated encryption and file data integrity
I've got a task to provide the integrity and an authenticated encryption for files in our application. I need an assurance if my way of thinking is correct.
I can't use AES GCM, I have to stay with ...
user66005