zQXQaN2w

1Encryption:
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5NSString * _secret = @"This the sample text has to be encrypted"; // this is the text that you want to encrypt.
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9NSString * _key = @"shared secret"; //secret key for encryption. To make encryption stronger, we will not use this key directly. We'll first hash the key next step and then use it.
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13key = [[StringEncryption alloc] sha256:key length:32]; //this is very important, 32 bytes = 256 bit
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17NSString * iv =   [[[[StringEncryption alloc] generateRandomIV:11]  base64EncodingWithLineLength:0] substringToIndex:16]; //Here we are generating random initialization vector (iv). Length of this vector = 16 bytes = 128 bits
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21NSData * encryptedData = [[StringEncryption alloc] encrypt:[secret dataUsingEncoding:NSUTF8StringEncoding] key:key iv:iv];
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25NSLog(@"encrypted data:: %@", [encryptedData  base64EncodingWithLineLength:0]); //print the encrypted text
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27Encryption = [plainText + secretKey + randomIV] = Cyphertext
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31Decryption:
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37encryptedData = [[StringEncryption alloc] decrypt:encryptedData  key:key iv:iv];
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39NSString * decryptedText = [[NSString alloc] initWithData:encryptedData encoding:NSUTF8StringEncoding];
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41NSLog(@"decrypted data:: %@", decryptedText); //print the decrypted text