In the current era, internet development has forced data confidentiality to become more crucial. There are several file types that frequently exchanged through the internet, such as text, image, video, audio, and so on. Image file is the most frequently misused by the irresponsible internet user, thus image security is highly important to conduct. Cryptography is a field of study to keep up the confidentiality of data distributed through networks. In this study, authors conduct image security using the classical cryptography algorithm, Vigenere Cipher, and Affine Cipher, and both Vigenere Cipher and Affine Cipher are implemented in Three-pass Protocol to avoid exchanging keys. It is impossible for the attacker to obtain the key since each sender and recipient keeps the key securely. The purpose of this study is to implement Vigenere Cipher and Affine Cipher in Three-pass Protocol and perform a comparison based on encryption result and execution time at each stage of the Three-pass Protocol. The results show that Affine Cipher in Three-pass Protocol performs encryption better than Vigenere Cipher in Three-pass Protocol in terms of its encryption results. However, in terms of execution time, Affine Cipher in Three-pass Protocol takes execution time longer than Vigenere Cipher in Three-pass Protocol.