39 lines
1.3 KiB
Markdown
39 lines
1.3 KiB
Markdown
# Cryptographic Hash Functions
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## Random Jargon
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_If you made it this far you know what all of this is but we need these terms because "muh academic vernacular"_
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* Variable Length Input
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* Fixed size output
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```python
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a = {
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'first',
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'second',
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}
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```
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Both `first` & `second` as inputs result in distinct references of the same size.
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* One-way property
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You should **not** be able to use a hash result(i.e. reference) to find an input.
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In English: _Only inputs can find outputs, not the other way around._
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* Two-way property/ Collision-free Property
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**2** identical data inputs will map to the same output
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## What does a hash provide?
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* Integrity checks
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* Message Digest / Authentication
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_Hashes are not secure ffs_. When we say authentication we really mean that we are checking to ensure there has been no changes to the original message.
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_NOTE:_ this really doesn't guarantee anything in communications susceptible to man-in-the-middle attacks.
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Let's get real for minute: Think of it this way a message is like a car and the key is our hash. If the key doesn't fit in the slot then its not our car, **but** if we sent our car + key oversees whoever steals the car + key has full control and we lose security effectively. Using SSL is _kinda_ like putting that car + key combo in a box that nobody except the recipient can open.
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