In this example, you will learn simpleC++ program to encrypt and decrypt the string using two different encryption algorithms i.e. Caesar Cypher and RSA.
Encryption/Decryption using Caesar Cypher Algorithm |
Encryption/Decryption using RSA Algorithm |
Encryption basically means encoding a particular message or information so that it can’t be read by other person and decryption is the process of decoding that message to make it readable.
Method 1: C++ program to encrypt and decrypt the string using Caesar Cypher Algorithm.
- Nov 16, 2016 Encrypt Strings with Passwords - AES 256 & SHA256. Rate this: 4.95 (8 votes). I create a hash with SHA2 (256 bit) from the password, this hash is the key and IV in the AES Encryption. I was looking for a quick intro to AES 256 encryption to get me started and this was a nice article that helped me.
- An AES key, and an IV for symmetric encryption, are just bunchs of random bytes. So any cryptographically strong random number generator will do the trick. OpenSSL provides such a random number generator (which itself feeds on whatever the operating system provides, e.g. CryptGenRandom on Windows or /dev/random and /dev/urandom on Linux).
- Check out this post to learn more about using symmetric keys for both encryption and decryption in C#, specifically using.NET Core Visual Studio. AES algorithm supports 128, 198, and 256-bit.
Feels a bit like PHP code. PHP extends the key with zero valued bytes up to 128 bit (then 192 bit or 256 bit depending on the size). It uses the same idea for padding. Both are of course completely idiotic when it comes to cryptographic standards, but there it is. Oh, and many PHP sites use Rijndael with a block size of 256 bit instead of AES too.
We have used a simple method of adding and subtracting a key value for encryption and decryption.
For encrypting a string, key-value ‘2’ is added to the ASCII value of the characters in the string.
Similarly, for decrypting a string, key-value ‘2’ is subtracted from the ASCII value of the characters.
Let’s take a deeper look at the source code:
Output
![256 bit encryption key example 256 bit encryption key example](/uploads/1/2/6/0/126045659/407029889.png)
#Decrypting
Serial key for synapse x. Explanation
In the above program, if you change the value of key then the encrypted value will be different.
If the user enters other value than 1 or 2 it will show
Invalid Input
.Method 2: C++ program to encrypt and decrypt the string using RSA algorithm.
RSA algorithm is bit complex than Ceaser Cypher. It involves the use of public and private key, where the public key is known to all and used for encryption.
On the other hand, Private key is only used to decrypt the encrypted message.
Here is the deeper look at the steps of encryption algorithm:
1: Creating Keys
- Select two large prime numbers x and y
- Compute
n = x * y
wheren
is the modulus of private and the public key - Calculate totient function,
ø (n) = (x − 1)(y − 1)
- Choose an integer
e
such thate
is coprime toø(n)
and1 < e < ø(n)
.e
is the public key exponent used for encryption - Now choose
d
, so thatd · e mod ø (n) = 1
, i.e., >code>d is the multiplicative inverse ofe
in mod ø (n)
2: Encrypting Message
Messages are encrypted using the Public key generated and is known to all.
The public key is the function of both
e
and n
i.e. {e,n}
.https://potentarcade.weebly.com/windows-7-professional-64-bit-key-generator-online.html. If
M
is the message(plain text), then ciphertext3: Decrypting Message
The private key is the function of both
d
and n
i.e {d,n}
.C Programming Generate A 256 Bit Encryption Key Generator
If
C
is the encrypted ciphertext, then the plain decrypted text M
isYou might be wondering how to write a source code for this program.
256 Bit Encryption Free
So let’s look at the program.
Output
This is all about encryption and decryption program in C++.