Popular recipes tagged "hash"

Hivemind (Python)

2015-07-15T12:37:13-07:00

Python recipe 579082 by Oscar Byrne (borg, defaultdict, hash, hashing, hivemind, python, singleton, state).

Inspired by the ever-popular Borg pattern, objects inheriting from Hivemind share state if initialised with the same arguments

Hashing Nonhashable / Mutable Objects (Python)

2015-04-16T12:11:34-07:00

Python recipe 579047 by Max Moroz (hash, python, python3). Revision 2.

This class is intended as a wrapper for non-hashable objects (such as lists, dictionaries, etc.) in situations where the object is known to be immutable. Example: memoization of function arguments.

Feedback much appreciated, I will update to reflect any comments.

Hash collision probability / Birthday problem (Python)

2012-12-21T09:32:54-08:00

Python recipe 578387 by Sander Evers (birthday, collision, hash).

Calculates the probability that, when making k random selections out of n possibilities, at least two of the selections are the same. See: http://en.wikipedia.org/wiki/Birthday_problem

What is the probability that (at least) two people in a class of 30 share their birthday?

>>> collide(30,365)
0.7063162427192688

What is the probability that ORA_HASH generates the same hash when hashing 25000 values?

>>> collide(25000,int(4.3e9))
0.07009388771353198

bubblebabble (Python)

2012-11-03T09:28:41-07:00

Python recipe 578319 by Space Hobo (babble, bubble, digest, hash, human, readable).

This module provides a bubblebabble function, which computes a (somewhat more) human readable format for message digests.

Checking hashes of files (Ruby)

2012-11-19T08:45:51-08:00

Ruby recipe 578339 by greg zakharov (hash, ironruby, md5, ripemd160, sha1, sha256, sha384, sha512).

There is HashAlgorithm class in System.Security.Cryptography namespace which is stored into mscorlib, a core assembly of .NET Framework. So...

Getting the SHA-1 (or MD5) hash of a directory (Python)

2009-12-06T19:02:40-08:00

Python recipe 576973 by Stephen Akiki (directory, getting, hash, md5, sha_1, the). Revision 4.

http://akiscode.com/articles/sha-1directoryhash.shtml

By definition a cryptographic hash is, "a deterministic procedure that takes an arbitrary block of data and returns a fixed-size bit string, the (cryptographic) hash value, such that an accidental or intentional change to the data will change the hash value".

Usually these hashes are used on files to "fingerprint" them, but in order to do the same to a directory you have to do something like this:

Generate a salt (PHP)

2012-07-10T19:52:17-07:00

PHP recipe 576894 by Xavier L. (crypt, generation, generator, hash, pass, password, salt, secure, security, string). Revision 6.

This function will generate a salt for use with passwords ranging using characters in range a to z, A to Z, 0 to 9 and !@#$%&?. The characters are sorted in a random value and can appear more than one time in the string. This way, this function is more powerful than the *shuffle() function. This means that the salt could also be longer than the character list.

Hash text simply (PHP)

2012-04-30T21:43:00-07:00

PHP recipe 576893 by Xavier L. (crypt, extensible, generator, hash, php, secure, security, simple). Revision 5.

This is a simply and extensible script that can be used to rapidly has any amount of text using PHP's hash() built-in function.

It recognizes when the page is loaded for the first time and displays a form with options. Afterward, it display the selected hash(es), with a link at the bottom to start again.

Create SHA Hashes of a Directory (Python)

2009-04-14T08:10:26-07:00

Python recipe 576716 by andrew.canit (encryption, hash, security, sha). Revision 2.

Walk through a Directory creating SHA Hashes of each file path