Our modern technologies are increasingly moving towards cryptography to secure the data transmission via a wireless medium. This is because transmission via wireless media is convenient to the modern world, but there still exists a major drawback cryptography in the name of Security. The Vigenere cipher belongs to the family of ciphers in which the cipher text is the ‘sum’ of the plaintext and some keystream. The Vigenere cipher is the encryption technique used in most of the communications, particularly in SMS encryption and decryption. The Vigenere key stream is not random, and therefore the cipher is vulnerable to attack. The plaintext attack and dictionary attack are the most commonly occurring attack leading to man in the middle attack. To overcome these two common attacks in vigenere cipher, we propose a noble approach that uses numbers instead of English alphabets to generate the key. © 2020, Springer Nature Switzerland AG.