A cryptographic hash function is an exceptional class of hash function that has certain properties that make it appropriate for use in cryptography. It is a numerical algorithm that maps information of self-assertive size to a piece line of a fixed size (a hash function) which is intended to likewise be a one-way output function, that is, a function which is infeasible to revert.
hashlib module
To calculate the cryptographic hash value in Python, “hashlib” Module is used. The hashlib gives the following cryptographic hash functions to discover the hash output of a text as follows:
- sha3_224 – 28 bit Digest-Size
- sha3_256 – 32 bit Digest-Size
- sha3_384 – 48 bit Digest-Size
- sha3_512 – 64 bit Digest-Size
This module actualizes a typical interface to various secure hash and message digest calculations. Included are the FIPS secure hash calculations SHA1, SHA224, SHA256, SHA384, and SHA512 just as RSA’s MD5 calculation (characterized in Internet RFC 1321). Earlier calculations were called message digests, but today it is secure hash.
Python has a bountiful help for hash code calculations through the library module hashlib. You can utilize the “hashlib.algorithms_available” to get the rundown of all accessible hash calculations in your variant of Python.
Hashlib provides the following constant attributes:
- “hashlib.algorithms_guaranteed” – A set which contains all the hashing algorithms which are guaranteed to be supported by this module on all platforms.
- “hashlib.algorithms_available” – A set that contains all the names of the hashing algorithms that are currently available in the interpreter.
Python3
import hashlib print(hashlib.algorithms_guaranteed)print(hashlib.algorithms_available) |
Output :
{‘blake2b’, ‘shake_256’, ‘sha512’, ‘sha3_224’, ‘sha384’, ‘sha3_512’, ‘sha3_256’, ‘sha3_384’, ‘md5’, ‘sha256’, ‘sha224’, ‘sha1’, ‘blake2s’, ‘shake_128’}
{‘SHA512’, ‘md5’, ‘blake2s’, ‘sha512’, ‘DSA-SHA’, ‘whirlpool’, ‘sha224’, ‘sha3_256’, ‘DSA’, ‘blake2b’, ‘MD5’, ‘SHA256’, ‘ecdsa-with-SHA1’, ‘dsaWithSHA’, ‘sha384’, ‘md4’, ‘sha3_384’, ‘MD4’, ‘sha3_512’, ‘sha256’, ‘RIPEMD160’, ‘ripemd160’, ‘shake_256’, ‘SHA’, ‘sha3_224’, ‘dsaEncryption’, ‘SHA224’, ‘sha’, ‘SHA1’, ‘sha1’, ‘shake_128’, ‘SHA384’}
Constant attributes
- hash.digest_size: The size of the subsequent hash in bytes.
- hash.block_size: The inside square size of the hash calculation in bytes.
- hash.name: The sanctioned name of this hash, consistently lowercase and always appropriate as a boundary to new() to make another hash of this sort.
Methods in hashlib
- hash.update(data): Update the hash object with the bytes-like object.
- hash.digest(): Return the condensation of the information went to the update() method up until now. This is a bytes object of size digest_size and can contain bytes ranging in number from 0 to 255.
- hash.hexdigest(): Like digest() aside from the digest is returned as a string object of twofold length, containing just hexadecimal digits.
- hash.copy(): Return a duplicate (“clone”) of the hash object. This can be utilized to effectively figure the overviews of information sharing a typical beginning sub-string.
SHAKE variable-length digests
- shake.digest(length): Returns the condensation of the information passed to the update() function . This is a bytes object of size which may contain bytes in the entire range from 0 to 255.
- shake.hexdigest(length): Like overview() aside from the condensation is returned as a string object of twofold length, containing just hexadecimal digits.
SHA – a brief
The Secure Hash Algorithms are a group of cryptographic hash functions proposed by the National Institute of Standards and Technology (NIST) and include:
- SHA-0: A word applied to the first form of the 160-bit hash function produced in 1993 under the name “SHA”. It was pulled back soon after production because of an undisclosed “noteworthy blemish” and supplanted by the marginally overhauled variant SHA-1.
- SHA-1: A 160-bit hash function which looks like the prior MD5. This was planned by the National Security Agency (NSA) to be essential for the Digital Signature Algorithm. Cryptographic shortcomings were found in SHA-1, and the standard was not, at this point endorsed for most cryptographic uses after 2010.
- SHA-2: A group of two comparative hash functions, with various block sizes, known as SHA-256 and SHA-512, they contrast in the word size; SHA-256 utilizations are of 32-byte words where SHA-512’s are of 64-byte words.
- SHA-3: A hash function, once in the past called Keccak, picked in 2012 after a public rivalry among non-NSA originators. It underpins similar hash lengths as SHA-2, and its inside structure varies altogether from the remainder of the SHA family.
SHA-3 implementation
Secure Hash Algorithm-3 additionally called Keccak, is a unidirectional method for creating computerized prints of the given length according to the standards as 224, 256, 384, or 512 pieces from input information of any size, created by a gathering of creators drove by Yoan Dimen in 2008 and embraced in 2015 as the new FIPS standard. The calculation works by methods for the blending capacity in with compression to the choose size “cryptographic sponge”.
Examples:
Input: HelloWorld
Output[sha3_224]: c4797897c58a0640df9c4e9a8f30570364d9ed8450c78ed155278ac0
Input: HelloWorld
Output[sha3_256]: 92dad9443e4dd6d70a7f11872101ebff87e21798e4fbb26fa4bf590eb440e71b
Input: HelloWorldOutput[sha3_384]: dc6104dc2caff3ce2ccecbc927463fc3241c8531901449f1b1f4787394c9b3aa55a9e201d0bb0b1b7d7f8892bc127216
Input: HelloWorld
Output[sha3_512]: 938315ec7b0e0bcac648ae6f732f67e00f9c6caa3991627953434a0769b0bbb15474a429177013ed8a7e48990887d1e19533687ed2183fd2b6054c2e8828ca1c
The following programs show the implementation of SHA-3 hash in Python-3.8 using different methods: Implementation of sha3_224 using the update method
Python3
import sysimport hashlibif sys.version_info < (3, 6): import sha3# initiating the "s" object to use the# sha3_224 algorithm from the hashlib module.s = hashlib.sha3_224()# will output the name of the hashing algorithm currently in use.print(s.name)# will output the Digest-Size of the hashing algorithm being used.print(s.digest_size)# providing the input to the hashing algorithm.s.update(b"Lazyroar")print(s.hexdigest()) |
sha3_224 28 11c044e8080ed87b3cf0643bc5880a38ae62dd4562390700000b1191
Implementation of sha3_256 using encode method
Python3
# import the library moduleimport sysimport hashlibif sys.version_info < (3, 6): import sha3# initialize a stringstr = "Lazyroar"# encode the stringencoded_str = str.encode()# create sha3-256 hash objectsobj_sha3_256 = hashlib.sha3_256(encoded_str)# print in hexadecimalprint("\nSHA3-256 Hash: ", obj_sha3_256.hexdigest()) |
Output:
SHA3-256 Hash: b05a48e99c60983b96b5a69efad8bb44e586702d484d43e592ab639ef64641ff
Implementation of sha3_384
Python3
# import the library moduleimport sysimport hashlibif sys.version_info < (3, 6): import sha3# initialize a stringstr = "Lazyroar"# encode the stringencoded_str = str.encode()# create sha3-384 hash objectsobj_sha3_384 = hashlib.sha3_384(encoded_str)# print in hexadecimalprint("\nSHA3-384 Hash: ", obj_sha3_384.hexdigest()) |
Output:
SHA3-384 Hash: b92ecaaafd00472daa6d619b68010b5f66da7c090e32bd4f5a6b60899e8de3e2c859792ec07a33775cfca8d05c64f222
Implementation of sha3_512 using the new method
Python3
import sysimport hashlibif sys.version_info < (3, 6): import sha3str = "Lazyroar"# create a sha3 hash objecthash_sha3_512 = hashlib.new("sha3_512", str.encode())print("\nSHA3-512 Hash: ", hash_sha3_512.hexdigest()) |
Output:
SHA3-512 Hash: 3706a96a8fa96b3fc5ff30cbca36ce666042e2d07762022a78a2ec82439848fc3695e83336ab71f47dddbc24b96454df2a437e343801a4e13faab89e8d0fda61
Applications of Hashing-Algorithms:
- Message Digest
- Password Verification
- Data Structures(Programming Languages)
- Compiler Operation
- Rabin-Karp Algorithm
- Linking File name and path together
