In cryptography, encryption is the process of encoding information to prevent an unauthorized party from reading it, and this process converts the original representation of the information, which is referred to as plaintext, into an alternative form called cipher text. There are many encryption algorithms; however, their performances have not been adequately evaluated. Many researchers have presented the performance analysis of public key cryptography using RSA (Rivest Shamir Adleman) and ECC (Elliptic Curve Cryptography) algorithms with different parameters of measurement and concluded that the use of smaller key sizes still provides some risk. Hence, this study evaluated the performances of RSA (Rivest Shamir Adleman), ECDH (Elliptic Curve Diffie-Hellman), ElGamal, and ECC (Elliptic Curve Cryptography) algorithms. Two hundred and thirty (230) Joint Photographic Expert Group (JPEG) medical images in the range 79.9kb to 829kb were downloaded online via www.kaggle.com and two video data (2.23mb) in Audio Video Interleave (avi), MPEG-4 (MP4) (2.23mb) were also downloaded online via www.youtube.com all were thereafter used as test bed. Individually, the image was converted to grayscale with pixel values between 0-255 characters; the video was split into frames, and converted to American Standard Code for Information Interchange (ASCII) corresponding value in order to increase the speed of encryption and decryption time. The algorithms were implemented using Matrix Laboratory (MATLAB R2016a), and the strengths of the algorithms were evaluated in terms of encryption time, decryption time and throughput