Difference between Secure Hash Algorithm (SHA) and Advanced Encryption Standard (AES)

Article:TECH161577  |  Created: 2011-06-03  |  Updated: 2011-06-07  |  Article URL http://www.symantec.com/docs/TECH161577
Article Type
Technical Solution

Environment

Issue



Want to understand the working of SHA and AES.


Solution



Secure Hash Algorithm (SHA) is a hashing algorithm. It is used for password (and other important info) hashing. SHA is used to create digital signatures of the data. By running the algorithm on the data, we produce the hash value (also known as signature). If the data changes in any way, the signature will not match and thus we would know that the data has been compromised/tampered with.

Its not an encryption algorithm. SHA cannot be used for encryption. We use SHA1 on earlier versions (before SEE 8.0.0) and SHA2 on SEE 8.0.0 and above for hashing.

Advanced Encryption Standard (AES) is an encryption standard (symmetric key encryption). Encryption algorithms have a a way of getting back the original data (in case of public/private key pair, the public key encrypts data and private key decrypts it). With symmetric keys, the same key can encrypt and decrypt. But hashing algorithms are one-way processes. Once you hash data and get the hash value, you cannot run it backwards on the hash value to get the original data
 




Article URL http://www.symantec.com/docs/TECH161577


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