Recently, privacy has become a major issue in digital images transmitted over public networks. Although the said environment is suitable and quite useful, the unfortunate reality is that there exist numerous privacy and security threats. This article addresses the problem by proposing a new image encryption technique using a chaotic system and bit-level circular shift. A Henon Map has been used as a chaotic system to do the bit-level circular shift to encrypt the image. According to the experimental results, the proposed algorithm overcomes the shortcomings of conventional encryption techniques. The proposed technique has lower computational complexity and shows promising results in terms of various security tests. The keyspace is too large to avoid brute-force attacks. For the encrypted image, the histogram is uniformly distributed and far away from the original image. Thus, the statistical attack is not applicable here. The correlation test of the adjacent pixels shows no correlation between them. The proposed algorithm is key sensitive; tiny key-value modifications will end up with another different image. Therefore, the new technique is compatible with real-time image-encryption applications over public networks.