MD5 :
“The MD5 message-digest algorithm is a widely used cryptographic hash function that produces a 128-bit (16-byte) hash value. Specified in RFC 1321, MD5 has been utilized in a wide variety of security applications, and is also commonly used to check data integrity. MD5 was designed by Ron Rivest in 1991 to replace an earlier hash function, MD4. An MD5 hash is typically expressed as a hexadecimal number, 32 digits long.” (1)
Terjemahan bebas :
MD5 adalah algoritma yang digunakan secara luas untuk menghasilkan nilai hash (128bit angka)yang telah digunakan secara luas untuk keamanan aplikasi, atau biasa digunakan untuk integritas data.
Dengan bahasa yang sederhana MD5 adalah algoritma untuk menciptakan identitas digital yang identik pada file.
Contoh penggunaan MD5 :
“MD5 hashes
The 128-bit (16-byte) MD5 hashes (also termed message digests) are typically represented as a sequence of 32 hexadecimal digits. The following demonstrates a 43-byte ASCII input and the corresponding MD5 hash:
MD5("The quick brown fox jumps over the lazy dog")
= 9e107d9d372bb6826bd81d3542a419d6
Even a small change in the message will (with overwhelming probability) result in a mostly different hash, due to the avalanche effect. For example, adding a period to the end of the sentence:
MD5("The quick brown fox jumps over the lazy dog.")
= e4d909c290d0fb1ca068ffaddf22cbd0
The hash of the zero-length string is:” (1)
MD5("")
= d41d8cd98f00b204e9800998ecf8427e
Dari contoh diatas dapat disimpulkan bahwa perubahan sekecil apapun terhadap suatu data/file akan merubah nilai hash/MD5 secara keseluruhan, sehingga algoritma ini digunakan secara luas untuk keamanan komputer.
SHA :
“The Secure Hash Algorithm is a family of cryptographic hash functions published by the National Institute of Standards and Technology (NIST) as a U.S. Federal Information Processing Standard (FIPS), and may refer to:-
- SHA-0: A retronym applied to the original version of the 160-bit hash function published in 1993 under the name “SHA”. It was withdrawn shortly after publication due to an undisclosed “significant flaw” and replaced by the slightly revised version SHA-1.
- SHA-1: A 160-bit hash function which resembles the earlier MD5 algorithm. This was designed by the National Security Agency (NSA) to be part of the Digital Signature Algorithm. Cryptographic weaknesses were discovered in SHA-1, and the standard was no longer approved for most cryptographic uses after 2010.
- SHA-2: A family of two similar hash functions, with different block sizes, known as SHA-256 and SHA-512. They differ in the word size; SHA-256 uses 32-bit words where SHA-512 uses 64-bit words. There are also truncated versions of each standardized, known as SHA-224 and SHA-384. These were also designed by the NSA.
- SHA-3: A hash function formerly called Keccak, chosen in 2012 after a public competition among non-NSA designers. It supports the same hash lengths as SHA-2, and its internal structure differs significantly from the rest of the SHA family.
The corresponding standards are FIPS PUB 180 (original SHA), FIPS PUB 180-1 (SHA-1), FIPS PUB 180-2 (SHA-1, SHA-256, SHA-384, and SHA-512). NIST has said that FIPS 180-5 will include SHA-3.” (2)
Contoh penggunaan SHA3 :
“Examples of SHA-3 (Keccak) variants
Note: Pending the standardization of SHA-3, there is no specification of particular SHA-3 functions yet.
Hash values of empty string.
Keccak-224("")
0x f71837502ba8e10837bdd8d365adb85591895602fc552b48b7390abd
Keccak-256("")
0x c5d2460186f7233c927e7db2dcc703c0e500b653ca82273b7bfad8045d85a470
Keccak-384("")
0x 2c23146a63a29acf99e73b88f8c24eaa7dc60aa771780ccc006afbfa8fe2479b2dd2b21362337441ac12b515911957ff
Keccak-512("")
0x 0eab42de4c3ceb9235fc91acffe746b29c29a8c366b7c60e4e67c466f36a4304c00fa9caf9d87976ba469bcbe06713b435f091ef2769fb160cdab33d3670680e
Even a small change in the message will (with overwhelming probability) result in a mostly different hash, owing to the avalanche effect. For example, adding a period to the end of the sentence: “ (2)
Keccak-224("The quick brown fox jumps over the lazy dog")
0x 310aee6b30c47350576ac2873fa89fd190cdc488442f3ef654cf23fe
Keccak-224("The quick brown fox jumps over the lazy dog.")
0x c59d4eaeac728671c635ff645014e2afa935bebffdb5fbd207ffdeab
Keccak-256("The quick brown fox jumps over the lazy dog")
0x 4d741b6f1eb29cb2a9b9911c82f56fa8d73b04959d3d9d222895df6c0b28aa15
Keccak-256("The quick brown fox jumps over the lazy dog.")
0x 578951e24efd62a3d63a86f7cd19aaa53c898fe287d2552133220370240b572d
Keccak-384("The quick brown fox jumps over the lazy dog")
0x 283990fa9d5fb731d786c5bbee94ea4db4910f18c62c03d173fc0a5e494422e8a0b3da7574dae7fa0baf005e504063b3
Keccak-384("The quick brown fox jumps over the lazy dog.")
0x 9ad8e17325408eddb6edee6147f13856ad819bb7532668b605a24a2d958f88bd5c169e56dc4b2f89ffd325f6006d820b
Keccak-512("The quick brown fox jumps over the lazy dog")
0x d135bb84d0439dbac432247ee573a23ea7d3c9deb2a968eb31d47c4fb45f1ef4422d6c531b5b9bd6f449ebcc449ea94d0a8f05f62130fda612da53c79659f609
Keccak-512("The quick brown fox jumps over the lazy dog.")
0x ab7192d2b11f51c7dd744e7b3441febf397ca07bf812cceae122ca4ded6387889064f8db9230f173f6d1ab6e24b6e50f065b039f799f5592360a6558eb52d760
Dari contoh diatas dapat disimpulkan SHA3 mempunyai algoritma yang lebih kuat daripada MD5, hal ini dapat dilihat secara gampang dari jumlah bit hasil hash nya.
Berikut ini adalah beberapa website tentang jebolnya MD5 :
Source :
1.http://en.wikipedia.org/wiki/MD5
1.http://en.wikipedia.org/wiki/MD5
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