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Can hashing be repeated?
A performance analysis of an overflow handling method for hash files, here called repeated hashing, is reported. It is concluded, however, that the usefulness of repeated hashing is in doubt because there are methods having the same performance but requiring less maintenance.
What is a 32 bit hash?
The 32-bit long hash value is a hexadecimal number of 8 characters. MD4 is a Message Digest Algorithm developed by Ronald L. Rivest from RSA Data Security, Inc. Currently it’s considered insecure, but it’s very fast on 32-bit mashines and it’s used for calculating EDonkey 2000 hashes in the EDonkey p2p network.
Is multiple hashing more secure?
No, multiple hashes are not less secure; they are an essential part of secure password use. Iterating the hash increases the time it takes for an attacker to try each password in their list of candidates. You can easily increase the time it takes to attack a password from hours to years.
How to hash 64 bit values to 32 bit values?
Instead of trying to hash the 64-bit values to other 64-bit values directly, we can hash them to 32-bit values. If you repeat twice (using two different hash functions), you get the 64-bit result you seek. All that is needed per hash function are three 64-bit values chosen at random, and then two multiplications, two additions and a single shift.
How many multiplications are needed for a 64 bit hash function?
All that is needed per hash function are three 64-bit values chosen at random, and then two multiplications, two additions and a single shift. The two multiplications are faster than they appear because they can be executed simultaneously as there is no data dependency. Two get a full 64-bit output, you thus need four multiplications.
Which is fast strongly universal 64 bit hashing everywhere?
Fast strongly universal 64-bit hashing everywhere! In software, hashing is the process of taking a value and mapping it to a random-looking value. Suppose you are given 64-bit integers (a long in Java). You might want to “hash” these integers to other 64-bit values.
Do you know the number of hash values?
Assuming your hash values are 32-bit, 64-bit or 160-bit, the following table contains a range of small probabilities. If you know the number of hash values, simply find the nearest matching row.