The mangrove woodland is a distinct bush or brine habitat characterized by a coastal sedimentation environment in which fine sediment (often rich in organic matter) accumulates in areas protected from high energy waves. Mangrove forests thrive on the coasts of tropical and subtropical regions, including Indonesia. Mangrove forest is a complex ecosystem that has a high diversity of plants, microorganisms, and animals. One of them is the Oil Mangrove (R. apiculata) which grows well on the coast of Lampung. This plant is hard, rich in tannins, and dense, mainly used to make charcoal and firewood. This plant traditionally used to treat diarrhea and nausea. Mangrove plants are tolerant to high salt levels, this special trait is due to the presence of secondary metabolites produced in response to various environmental stresses. Flavonoid compounds, alkaloids, terpenoids and steroids are secondary metabolites produced by mangrove plants. Secondary metabolite compounds from mangroves have bioactivity such as antidiabetic, antimicrobial, antioxidant and anticancer. Exploration of secondary metabolites from mangroves, especially oil mangroves locally named as Bakau Minyak, which are widely grown in the Lempasing area, coastal Lampung for the development of medicinal compounds, has not been intensely reported. This investigation aims to study the potential phytochemicals profile of R. apiculata’s leaf as an antioxidant

Vigenère cipher is a classical cryptography algorithm and similar to other classical algorithms, it produces smaller but less secure ciphertexts than a public key cryptography algorithm. Meanwhile, Rabin-p is a public key cryptography algorithm with a stronger encryption than Vigenère cipher. Nevertheless, as a public key algorithm, Rabin-p is inefficient to encrypt vast amounts of messages such as BMP image files, since the size of the cipherimages will increase manyfold and this would lead to a problem in storing and sending the cipherimages. To overcome these problems, in this study, we combined the Vigenère cipher and the Rabin-p algorithm in a hybrid cryptosystem scheme. In the experiment, the Vigenère cipher was used to encrypt the BMP files and the Rabin-p algorithm was used to encrypt the Vigenère keys. The result showed that the size of the cipherimages did not increase and the decryption procedure could recover the original BMP files while maintaining their integrity.