Setia Astuti

Bio: Setia Astuti is an academic researcher. The author has contributed to research in topics: Steganography & One-time pad. The author has an hindex of 1, co-authored 2 publications receiving 17 citations.

An improved secure image hiding technique using PN-sequence based on DCT-OTP

Abstract: The security of sending confidential data on the internet is very important. Thus, the data security techniques must be developed. Techniques like cryptography and steganography are techniques that are widely used to protect information messages that are confidential. Steganography is a technique to hide, while cryptography is a technique to encode. The combination of the two techniques produces a better security system. This paper proposed a combination of steganography and cryptography by using Discrete Cosine Transform (DCT), One Time Pad (OTP) and PN-Sequence implemented on a digital image. The test and measurement method used to determine the quality of stego image or final image is using Peak Signal to Noise Ratio (PSNR) and Mean Square Error (MSE). On the other hand, Normalized Correlation Coefficient (NCC) is used to measure the quality of extraction and decryption messages from the proposed StegoCrypt method. The experimental results of this study get better results compared to previous studies where this technique has better imperceptibility and is more resistant to JPEG compression, median filter, and crop attacks.

Eggs Classification based on Egg Shell Image using K-Nearest Neighbors Classifier

Abstract: Chicken eggs are one of the foods that are widely consumed by humans. The quality of eggs will affect the nutritional quality of eggs. One method that can be used to determine the quality of the outer shell is the quality of the eggshell. This research proposes egg classification techniques based on eggshell images using the K-Nearest Neighbors (KNN) classifier based on two feature extractions, namely the extraction of Hue Saturation Value (HSV) color features, and the Gray Level Co-Occurrence Matrix (GLCM). The experiment was carried out using 100 egg images consisting of three classes, namely eggs of good quality, rotten, and defective. Of the 100 images used 21 images as testing images and the rest as training images. The test was conducted with parameter values k = 1.3, and 9 while the distance used for each k was 1.2, and 4. Based on the test results obtained the highest accuracy of 85.71%, where the parameter value k = 1; d = 2 and k = 1; d = 4.

An improved message capacity and security using divide and modulus function in spatial domain steganography

Abstract: Image Steganography is a technique for hiding messages into digital images, so messages cannot be perceived by the human senses. The two most important aspects of steganography techniques are the payload capacity and imperceptibility of embedded messages. This research proposes a method to explode secret messages using divide and modulus functions so that the message capacity embedded in a digital image can increase. The divide and modulus function can also improve message security because the messages are split into two part and sent separately. One part embedded and the other is stored as a key extraction. This method is done in a spatial domain. Spatial domains are steganographic techniques performed by manipulating pixel values directly. LSB is one of the most popular spatial domains proposed in this research. To measure the quality of imperceptibility are used PSNR and MSE. Based on the experimental results of this study proved that the capacity of embedded messages can increase twofold and keep maintaining the imperceptibility quality.

A Comparative Study of Image Cryptographic Method

Abstract: Cryptography is a technique that is widely used to secure data transactions, this technique has also been widely used to secure digital images. There are several cryptographic techniques that are widely used in digital imagery, such as Arnold Transform, Rivest Code 4 (RC4) and One-time pad (OTP). This research aims to compare the performance of these three techniques on digital images. Performance of each encryption method is measured using entropy, SSIM, NPCR, UACI, computation time and histogram analysis. While the decrypted image is measured by the correlation coefficient and computation time using tic toc function. Based on the test results can be concluded that Arnold transforms algorithm only do a scramble on the image based on a certain iteration, so that the entropy and histogram values remain the same as the original image, only visually the image looks random and meaningless. RC4 has an advantage on entropy value and should not require a very long key, so it does not have to be a special memory to store the key. While OTP has advantages in the fastest computing time, and also superior values in NPCR, UACI, and SSIM. A random key of the same size as the original image makes encryption hard to decrypt. Although the size of the key to making the algorithm must provide a larger space for key storage.

Imperceptible and secure image watermarking using DCT and random spread technique

Abstract: Watermarking is a copyright protection technique, while cryptography is a message encoding technique. Imperceptibility, robustness, and safety are aspects that are often investigated in watermarking. Cryptography can be implemented to increase watermark security. Beaufort cipher is the algorithm proposed in this research to encrypt watermark. The new idea proposed in this research is the utilization of Beaufort key for watermark encryption process as well as for spread watermark when inserted as PN Sequence substitute with the aim to improve imperceptibility and security aspects. Where PN Sequence is widely used in spread spectrum watermarking technique. Based on the experimental results and testing of the proposed method proved that imperceptibility and watermark security are increased. Improved imperceptibility measured by PSNR rose by about 5dB and so did the MSE score better. Robustness aspect is also maintained which has been proven by the excellent value of NCC.