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Can hash be modified?
There is a very very very low mathematical probability that the container could be modified without changing both SHA1 and MD5. There are known collision attacks on both hashes, however one would need to produce an still valid ciphertext that can be decrypted and this would make it hard.
What type of attack can compromise a hash function?
encryption collision attack
A successful encryption collision attack on a cryptographic hash function could compromise the security of all kinds of digital systems.
How hash collision can be used by an attacker for malicious purposes?
If an attacker can craft a hash collision, they could use it to create two different files that share the same SHA-1 hash value. Systems that rely on hashes to validate the authenticity of data such as code repositories and backups could be deceived into accepting a malicious file in place of the genuine file.
Why do hash values change when data is modified?
The hash file is changed when the data is modified because the information within the file has changed and it is considered a new/different file.
Which two algorithms are used for hash?
SHA-2 basically consists of two hash algorithms: SHA-256 and SHA-512. SHA-224 is a variant of SHA-256 with different starting values and truncated output. SHA-384 and the lesser-known SHA-512/224 and SHA-512/256 are all variants of SHA-512.
Which is the one way mechanism for hashing data?
Thus, in contrast to encryption, hashing is a one-way mechanism. The data that is hashed cannot be practically “unhashed”. Commonly used hashing algorithms include Message Digest (MDx) algorithms, such as MD5, and Secure Hash Algorithms (SHA), such as SHA-1 and the SHA-2 family that includes the widely used SHA-256 algorithm.
Which is hash function is not pre-image resistant?
For example, cyclic redundancy check (CRC) is a hash function used in network applications to detect errors but it is not pre-image resistant, which makes it unsuitable for use in security applications such as digital signatures.
Can a hash function be used to protect passwords?
A hashing function takes arbitrary inputs and transforms them into outputs of a fixed length. To qualify as a cryptographic hash function, a hash function must be pre-image resistant and collision resistant. Due to rainbow tables, hashing alone is not sufficient to protect passwords for mass exploitation.
Which is the best algorithm for hashing data?
The data that is hashed cannot be practically “unhashed”. Commonly used hashing algorithms include Message Digest (MDx) algorithms, such as MD5, and Secure Hash Algorithms (SHA), such as SHA-1 and the SHA-2 family that includes the widely used SHA-256 algorithm.