Online Backup Application - Security,compression etc

[Nuv]

Hi guys,

 

I would like to make a web backup application where backed up data will be stored in the cloud server. I have few questions about security and compression.

 

1. I need a good compression algo/technique. CPU usage is a bit critical. After some research, i see gzip is apt for my needs. Is that right ?

 

2. I need some encryption algo too. After reading book on Applied Cryptography by Bruice Schneier and research, i found that AES is pretty good. Should i be using that ?

 

3.Will i have/need to check for data integrity (by hashing algos like SHA-1 and MD5) too ? Or its used only for message integrity checking ?

 

4. In what order should the process flow ? Compression then Encryption or vice- versa ?

 

5. Am i missing anything, security related ? Use encryption algo, data integrity(if its necesarry) and send it to the cloud server where itll be stored that way.

 

 

Thankyou.