Questions tagged [checksum]
A checksum is a value created from a binary file that can be used to detect errors especially occurred in the transmission.
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Is it possible to fake any file's SHA256 checksum with Length extension attack? Is SHA256 completely insecure when file size is not also checked?
Can fake SHA256 checksum be created trivially for any file by attacker after padding some data after original file i.e. using length extension attack?
E.g:
Alice creates fake linux installation ISO ...
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How Should Multiple Checksums Be Performed On the Same Data?
I am using CRC32 to verify the integrity of received UDP packets. Along with the generator polynomial, the sender will also specify how many checksums to perform on the sent data, as well as what ...
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Is there an accepted way to cryptographically enforce tracked changes on a document?
I'm working on a document-editor project, and I would like to add a feature to lock tracked changes, similar to Microsoft Office. The goal is to allow one user to lock tracked changes with a password,...
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Check correctness of data using only publicly known variables and a server response
A smart contract (a publicly known program) needs to check if the data D is correct (belongs to some fixed set). It is by definition correct if our trusted server checks it and decides it's correct.
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Is CRC32C (any) better than CRC32(B)?
Is CRC32C (any) better than CRC32(B)?
I read that CRC32C (alias Castagnoli) is better than CRC32 (sometimes referred as CRC32B) in detecting errors but what that exactly means and how to check it ...
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Identifying identical files without reading them completely
Imagine the following situation:
there are many "big" files (100Gb+) lying on 2 different remote servers
you have no direct access to these files
you can only read a small amount of each file (e.g. ...
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Winternitz One Time Signature
I happened to watch Mr. Bill Buchanan lecture that explains Winternitz one time signature scheme (https://www.youtube.com/watch?v=eqMMlcN4zSc). The scheme shown in the lecture is susceptible to ...
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Do all files have a hash / checksum?
I am curious If every single digital file has a hash and/or a checksum. When verifying my downloaded files using hdiutil on mac os, about 90% of my files report some sort of checksum. However, when i ...
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Is it feasible to get a hash collision for CRC32, MD-5 and SHA-1 on one file?
I'm aware that individually, each has its weaknesses (especially CRC32), but is it feasible that a file could be created to falsely match all three?
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Are LRC (Longitudinal Redundancy Check) or CRC (Cyclic Redundancy Check) of any use in modern day computing?
I am currently learning about the history of Data integrity / Error detection.
In the old days of tape drives, LRC was used for error detection. They were also used (at certain point in time) for ...
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Verify partial message given hash of full message
I need to verify partial downloads (retrieved sequentially), given a (preferably short) hash of the complete download.
Given a message $m_0 \mathbin\| m_1 \mathbin\| m_2 \mathbin\| \cdots$, hash ...
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Suitable 16-bit checksum?
I am writing a toy1 transport protocol and I am trying to implement a feature whereby:
A 16-bit checksum is included in every packet.
This checksum can be extended to be 48-bit if the data is large, ...
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Blake2 vs md5 for checksum / file integrity
I'm working on something that requires computing a checksum / file integrity. I've heard MD5 was no longer recommended. Should I use Blake2 instead? Is there a specific variant of Blake2 I should use ...
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How can I calculate the feasibility of brute-forcing missing secret shares against the secret checksum?
Secret sharing has the problem of player cheating, where a forged share $s'_i$ can be sent to generate a fake secret $m'$ during reconstruction (and the cheaters can even collude to generate the real ...
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Why does WOTS+ need a checksum during signing operation?
I was reviewing WOTS+ scheme for consideration in our private blockchain, and noticed that it had a small overhead of calculating a checksum as seen in the following pseudocode excerpt from the ...
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How to calculate a multiple-character checksum for authentication using a tabula recta?
I am not sure if this is possible to do using a tabula recta, but I would like to know how to calculate a multiple-character checksum of a text. For a single-character checksum, it's easy. You just ...
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Why do digital signatures use a hash algorithm instead of a checksum?
Based on my knowledge, all digital signature algorithms use a hash function to sign a message, and then encrypt the hash result. So why do these algorithms not use a checksum instead of a hash ...
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Checksum vs. non-cryptographic hash
What are the differences between checksums (e.g. Fletcher, Adler, CRC), non-cryptographic hashes (e.g. xxHash, MurmurHash, CityHash) and cryptographic hashes (e.g. MD5, SHA1, SHA3)?
I am familiar ...
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Optimal way to get checksum digits from hash?
Let msg be some data we want to hash using an arbitrary digest size algorithm such as blake2b. From that hash, we would like to compute a checksum field with n decimal digits.
If we suppose that the ...
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1answer
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Using checksum instead of hash for authenticating ciphers
Lets assume for a specific situation we cannot use authenticated encryption like GCM ...
If we were to use CTR, what would you think of using a checksum on the plaintext then encrypt the whole.
The ...
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Can XTS + checksum be used for authenticated encryption?
Is it possible to use XTS + a checksum for authenticated encryption? Specifically, it seems like a good $n$ bit checksum applied before encryption should ensure that any change to the ciphertext will ...
