MD5 stands for message-digest algorithm. It is a cryptographic protocol used for authenticating messages as well as content verification and digital signatures. MD5 is based on a hash function that checks that a file it can sent matches and the file received by the person that it is sent to.MD5 message-digest algorithm is the 5th version of the Message-Digest Algorithm invented by Ron Rivest to make a 128-bit message digest. MD5 is quite rapid than other versions of the message digest, which creates the plain text of 512-bit blocks, which is more divided into 16 blocks, each of 32 bit ... Read More

Hill Cipher is a multiletter polyalphabetic cipher invented by Lester S. Hill cipher is a coding system by combining the notion of a matrix with the approach of linear congruence in the phase of encrypting a plaintext into a ciphertext and decrypting a ciphertext into a plaintext.Hill Cipher does not restore each of the same alphabets in plaintext with the same alphabet in ciphertext because it help matrix multiplication by encryption and decryption. Hill Cipher which is a polyalphabetic cipher can be categorized as a block cipher because the text to be handled will be divided into blocks of a ... Read More

MACMAC stands for Message Authentication Code. It is also defined as a tag. It can be used to authenticate the origin and characteristics of a message. MACs need authentication cryptography to check the legitimacy of information sent through a network or moved from one person to another.A MAC is created by a keyed secure hash function on a message. It can be used to provide the integrity of the message such that if a message secured by a MAC is tampered, it can be identified by comparing the MAC contained with in the message and the recalculated MAC.Message authentication codes ... Read More

SteganographySteganography is the procedure of hiding data, images, or audio messages within another element of information, image, or audio. Steganography is the art of hiding data.In computer science, it can define hiding information within a message or file. It serves a similar objective to cryptography, but rather than encrypting information, steganography easily hides it from the user.Invisible ink is an instance of steganography that is different to computers. A person can address a message with clear or "invisible" ink that can only be view when another ink or liquid is used to the paper.Similarly, in digital steganography, the main goal ... Read More

MAC stands for Message Authentication Code. It is a security code or tag that is further to the message sent by the sender to the receiver for supporting message authentication and integrity (no modification in message).MAC is similar to Message Digest (MD) except that it needs the symmetric key cryptography procedure to authenticate a message i.e., the similar key is shared among sender and receiver. The keyed hash function is second termed for the message authentication code. MAC is also defined as Cryptographic Checksum.A message authentication code (MAC) algorithm creates a message to be authenticated & a secret key that ... Read More

Steganography is an approach that simplify hiding of a message that is to be maintain secret within other message. This result is the secrecy of the hidden message itself. Steganography approach can be used to images, a video file or an audio file.The use of steganography such as watermarking which hides copyright data inside a watermark by overlaying document not easily invented by the naked eye. This avoids fraudulent actions and provides copyright secured media more protection.Advantage of SteganographyThe advantage of steganography is as follows −The advantage of steganography is that messages do not send consideration to themselves. Clearly detectable ... Read More

The main goals of frequency domain watermarking is to embed the watermarks in the spectral coefficients of the image. The most generally used transforms are the Discrete Cosine Transform (DCT), Discrete Fourier Transform (DFT), and Discrete Wavelet Transform (DWT).The main reason for watermarking in the frequency domain is that the nature of the human visual system (HVS) are better acquired by the spectral coefficients.Discrete cosine transforms (DCT) − DCT like a Fourier Transform. It can define data in terms of frequency space instead of an amplitude space. This is beneficial because that corresponds more to the method humans perceive light, ... Read More

HMAC stands for Keyed-Hashing for Message Authentication. It is a message authentication code acquired by running a cryptographic hash function (such as MD5, SHA1, and SHA256) over the information (to be authenticated) and a shared secret key. HMAC is defined in RFC 2104.HMACs are same as digital signatures. They both provide integrity and authenticity. They both need cryptography keys and they both apply hash functions. The major difference is that digital signatures need asymmetric keys, while HMACs need symmetric keys (no public key).HMAC can be used in sequence with some iterated cryptographic hash function. MD5 and SHA-1 are instance of ... Read More

A message authentication code is a block of a few bytes that can be used to authenticate a message. The receiver can test this block and be definite that the message hasn't been changed by the third party.A family of cryptographic functions that is parameterized by a symmetric key. Each functions can facilitate on input data (known as “message”) of variable length to create an output value of a definite length. The output value is known as the MAC of the input message.An approved MAC algorithm is normal to satisfy the following property (for each of its provided security levels): ... Read More

The spatial domain define the image in the form of pixels. The spatial domain watermarking embeds the watermark by changing the intensity and the colour value of some preferred pixels.The spatial domain watermarking is simpler and its calculating speed is high than transform domain but it is less powerful against attacks. The spatial domain techniques can be simply used to any image.There are various techniques of spatial domain watermarking which are as follows −Least Significant Bit (LSB) − The LSB is the easiest spatial domain watermarking technique to insert a watermark in the least significant bits of some randomly selected ... Read More