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| bio | website | |
|---|---|---|
| location | Ontario | |
| age | 39 | |
| visits | member for | 2 years, 6 months |
| seen | Mar 14 at 1:06 | |
| stats | profile views | 343 |
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Dec 23 |
awarded | Popular Question |
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Dec 22 |
awarded | Announcer |
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Nov 27 |
comment |
How to implement a safe password history @Mathew Foscarini The downside of generating a password for the user, and forcing them to use it, is that now it has to be written down - completely negating any of the security you were hoping to gain. |
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Oct 28 |
awarded | Yearling |
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May 25 |
comment |
Which hashing algorithm is best for uniqueness and speed? @LouisWasserman CityHash has no 32-bit version; so....no you can't see it covered :) |
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May 25 |
revised |
Which hashing algorithm is best for uniqueness and speed? added 15 characters in body |
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May 25 |
revised |
Which hashing algorithm is best for uniqueness and speed? Added mention of old thing article |
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May 4 |
comment |
Which hashing algorithm is best for uniqueness and speed? @maaartinus On the downside, as a practical matter (non-cryptographic) hash functions are usually used to implement a hash table. Hash tables are usually keyed by a string. Trying to pick our the correct 4 bytes of a guid so you can convert it to an integer, so you can convert it to a string adds needless complexity. And it also reduces the usefulness (e.g. if i want to find the item for CustomerGUID "{B5225B82-F3DE-41E7-A70B-91F5AB1F9709}") |
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Apr 28 |
awarded | Great Answer |
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Apr 28 |
revised |
Which hashing algorithm is best for uniqueness and speed? Added link to mention of SuperFastHash having poor collision resistance |
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Apr 28 |
comment |
Which hashing algorithm is best for uniqueness and speed? @maaartinus i've not hashed random data, nor would i see a value in doing so. On the other hand i do hash type 4 uuids (uuid's not tied to a MAC address). Storing customers in a hash table by their unique key does make sense. Thinking one can just take the first 32 bits of a 128-bit guid, and assume it has better collision resistance characteristics than an actual hash, is about as smart as me trying to invent my own hash algorithm. p.s. only 122 bits of type 4 random uuid are random. |
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Apr 28 |
comment |
Which hashing algorithm is best for uniqueness and speed? @Secure i've tested known inputs where available. The implementations may be wrong; but they're the implementations i'd be using - so the results are accurate for me. You're free to test the algorithms yourself. In practice i'll likely never see a collision. |
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Apr 27 |
revised |
Which hashing algorithm is best for uniqueness and speed? added 274 characters in body |
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Apr 26 |
revised |
Which hashing algorithm is best for uniqueness and speed? Everything i said about crc was mistaken |
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Apr 26 |
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Which hashing algorithm is best for uniqueness and speed? Now i'm wondering if randomness is a useful thing at all when looking for a hashtable implementation. Given virtual memory paging, cache lines, L2 cache - wouldn't i want the first 100 items i hash to fall into the first 100 slots of my list? Collisions are bad, and cause a hash-table probe, and speed is tremendously important. But randomness - not so much. |
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Apr 26 |
revised |
Which hashing algorithm is best for uniqueness and speed? added 672 characters in body |
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Apr 26 |
comment |
Which hashing algorithm is best for uniqueness and speed? @KonradRudolph That'll be tonight/tomorrow's task. The hardest part is transcoding these algorithms into Delphi. |
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Apr 26 |
revised |
Which hashing algorithm is best for uniqueness and speed? added 286 characters in body |
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Apr 26 |
revised |
Which hashing algorithm is best for uniqueness and speed? added MurMur |
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Apr 26 |
revised |
Which hashing algorithm is best for uniqueness and speed? added 996 characters in body |
