In this tutorial we are going to learn about encryption and decryption in cyber security
First we have to learn about what is Differene b/w RSA And DSA
- The performance of the two is what distinguishes one from the other
- DSA is faster generating key than RSA
- On the other hand RSA is faster encryption than DSA
- When decrypting, DSA is faster, mainly due to its great decryption capability
- If you need digital signing, DSA is the encryption algorithm of choice
- For verification of the digital signature RSA is the best choice.
- Depending on the circumstances, a choice will need to be made, but both DSA and RSA have equal encryption capabilities and the option with less demand on the resources should be chosen.
Now we are going to learn where is RSA Encryption used for
- RSA is used mostly in hybrid encryption schemes and digital signatures.
- In the former it is used to encrypt a symmetric key and send it to second party who has requested it.
- RSA is comparatively slow so you would never use it to encrypt a whole file.
- Instead the file is encrypted symmetrically and only the key is encrypted by RSA directly.
For Digital signatures one can use the private key to sign a message or file (or better: sign the cryptographic hash of the message/file, much faster). If a second party has the corresponding public key he can verify that the file is authentic and has not been altered or damaged.
- By that same logic it is trivially possible to build nonrepudiation schemes.
What is the difference between SHA-256, AES-256 and RSA-2048 bit encryptions?
- Firstly SHA, AES and RSA are three different types of encryption. Let us check them 1 by 1.
- RSA:- It is an asymmetric cryptography, i.e. it uses a key to encrypt data and then uses a different key for decryption. These are normally called a public key and a private key. The public key can be used to encrypt some data and then it would require a private key for its decryption.
- AES: It is a symmetric cryptography, i.e. it uses same key for both encryption and decryption.
- SHA: It is a hash algorithm, i.e. one way encryption. So that it gives no way for decryption
- Normally things like ‘passwords’ are kept using SHA algorithm in databases or other persistent form. Whereas files or text-data are encrypted using AES or RSA algorithm.
- This is because files or text-data are normally read by human and hence they must be decrypted for using.
- Passwords are used by computers to match and hence it works without being decrypted.
- Now those 256, 256 and 2048. They are basically the number of bits in the keys(or digest) of these algorithms.
- So the basic differences remains same with or without them.
SHA and AES
- SHA isn’t encryption. It is a family of “Secure Hash Algorithms” that have been developed by the National Security Agency and used to generate a hash of data. SHA cannot be used for encryption
- AES (Advanced_Encryption_Standard) is a symmetric encryption standard. It is is used to encrypt data, or prevent people from viewing that data with knowing some secret.
This is all what is encryption and decryption in cyber seurity