Hash Function for Data Controls

A hash function is a function that can be used to map data of arbitrary size to data of fixed size. The values returned by a hash function are called hash values, hash codes, hash sums, or simply hashes. 

Simple right? Nope. 

In data management efforts in the financial industry I have witnessed that there is a steep learning curve by the business partners who struggle to keep up with technology tools that help manage and govern data faster and smarter. I have been there so I know. There is lack of education and a certain expectation that everyone knows. The reality is quite different. So I want to discuss those things that people are expected to know but perhaps don't. 

Isn't hashing like encryption? No.

Hashing is not encryption. Encryption is a two-way function; what is encrypted can be decrypted with the proper key. Hashing, however, is a one-way function that scrambles plain text to produce a unique message digest. With a properly designed algorithm, there is no way to reverse the hashing process. 

You want a cool word- use cryptography instead. 

Most known hash algorithms are MD5 and SHA. So how they work? 

The MD5 hash function produces a 128-bit (16-byte) hash value, typically expressed in text format as a 32 digit hexadecimal number. This can be done to a data value or a data file. This control can be very useful to check for consistency/integrity purposes. If the hash value matches then the data/file is in its original form. Linux machines can easily do this without installing any software- you can open up Terminal and run it. For widows you probably have to download basic hash value generator. 

Nishas-MBP:Documents nishabalani$ md5 NISHA\ BALANI\ 10.20.14.docx 

MD5 (NISHA BALANI 10.20.14.docx) = 17c2d308bbc95f5652ad7d83d0c79abc

SHA stands for Secure Hash Algorithm. Same as Md5 in its applicability. SHA-2 specifically includes significant changes from its predecessor, SHA-1. The SHA-2 family consists of six hash functions with hash values that are 224, 256, 384 or 512 bits. The industry has moved away from MH5 since the SHA functions provide additional security. It is believed that when we run out of SHA we may evolve to more complex algorithms. 

Nishas-MBP:Documents nishabalani$ shasum -a 256 NISHA\ BALANI\ 10.20.14.docx 

2224919ca9ef7eb92ae2566ffeb6ee41bb7e4502c13afc3380ba93a9423d2ca5  NISHA BALANI 10.20.14.docx

I encourage you to play with this on your machines. Watch a helpful youtube video about step by step instructions. 

Let me know if this was helpful. Leave me a comment.