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### The difference between SHA, AES and RSA algorithm?

Posted: **Wed Dec 05, 2018 6:01 am**

by **Vlidda**

Can anybody popularize the basic knowledge of algorithm?

Such as what is the difference between SHA, AES and RSA algorithm?

### Re: The difference between SHA, AES and RSA algorithm?

Posted: **Mon Dec 10, 2018 6:36 am**

by **tay00000**

SHA -> digital data one way hashing.

AES -> digital content confidentiality protection via data scrambling.

RSA -> digital data confidentiality protection via data scrambling and also digital identity attestation and digital content verification via digital signatures.

### Re: The difference between SHA, AES and RSA algorithm?

Posted: **Mon Dec 24, 2018 6:14 am**

by **bigWhite**

AES is a symmetric block cipher algorithm

RSA is an asymmetric encryption algorithm

### Re: The difference between SHA, AES and RSA algorithm?

Posted: **Tue Dec 25, 2018 2:34 am**

by **Maggie**

I'm going to try to simplify things a little bit, and I'm going to introduce some metaphors that may not be appropriate, but hopefully will help you understand these three or these three types of algorithms.

SHA, digest algorithm.It can be imagined that a relatively large data block can be regarded as a whole, and the algorithm extracts the eigenvalues based on the whole data.Just like extracting a person's fingerprint can basically confirm a person's identity, when the summary value of a data block is correct, the integrity of the data can be confirmed.The algorithm can simplify the complexity of authentication system.However, it should be noted that the summary value is not unique to the original data block, and the summary data cannot be restored to the original data.The typical algorithm is also known as MD5.

AES symmetric algorithm, encryption key and decryption key the same.Used to encrypt a block of data and restore the original data using the key used at the time of encryption.It's as if two people each have the same key and can unlock the same lock.

See the following formula to understand symmetric encryption.

(the formula can use texture)

Encryption process E=f(T,K).Decryption process T=f(E,K).T plaintext, E ciphertext.

The typical algorithm is also known as DES and 3DES.

RSA asymmetric algorithm, encryption key and decryption key are different, is an important algorithm in PKI system.Let's take the example of opening the lock above. Two keys are different, so to speak, they are completely different, but they can open the same lock, which is not common in life, but you can try to understand it this way.Keys used to encrypt data can be different from keys used to decrypt data, an imaginative process that can be performed by a cryptographer and simplified to the function f.

(the formula can use texture)

E = f (T, pubK).Decryption process T=f(E,priK).PubK public key, priK private key.

Similar algorithms also have ECC.