Notes

#Function f#Function for CaeserCipher
#input-> plainText and KeyValue
#output -> return Cipher text encrypted using keyvalue
#the logic we are going to use is: increment the ascii value for each character #with the given value and mod by 26 will give the appropriate alphabet
def CaeserCipherEncrypt(plainText):
#Initialize a string for cipher text
cipherText = ""
#Iterate through each character in the plain text
for i in range(len(plainText)):
ch = plainText[i]
#Check for odd and encrypt it
if (i % 2 != 0):
cipherText += chr((ord(ch) - 1 - 65) % 26 + 65)
#Check for even and encrypt it
else:
cipherText += chr((ord(ch) + 5 - 97) % 26 + 97)
return cipherText
def CaeserCipherDecrypt(cipherText):
#Initialize a string for plain text
plainText = ""
#Iterate through each character in the cipher text
for i in range(len(cipherText)):
ch = cipherText[i]
#Check for odd and decrypt it
if (i % 2 != 0 ):
plainText += chr((ord(ch) + 1 - 65) % 26 + 65)
#Check for even and decrypt it
else:
plainText += chr((ord(ch) - 5 - 97) % 26 + 97)
return plainText

plainText = input("Enter any plain Text: ")
print("Cipher Text: ",CaeserCipherEncrypt(plainText))
print("Plain Text: ",CaeserCipherDecrypt(CaeserCipherEncrypt(plainText)))