Speech encryption and decryption

LFSR algorithm is appropriate for the encryption and decryption of online streaming data, e. VoIP voice chatting over IP. This paper is implemented the encryption module of speech signals to cipher text and decryption module of cipher text to speech signals. Google Scholar. Alvarez G, Li S Some basic cryptographic requirements for chaos-based cryptosystems. Int J Bifurc Chaos 16 8 — Biswas D, Banerjee T A simple chaotic and hyper-chaotic time-delay system: designand electronic circuit implementation.

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Slimania D, Merazka F Encryption of speech signal with multiple secret keys. Typical encryption techniques use mathematical operations to transform a message represented as a number or a series of numbers into a ciphertext. Mathematical operations called one way functions are particularly suited to this task. A one way function is one which is comparatively easy to do in one direction but much harder to do in reverse.

The RSA system uses one way functions of a more complex nature [7]. Specifically, the system uses modular arithmetic to transform a message into unreadable ciphertext. Modular arithmetic is often called "clock" arithmetic, because addition, subtraction, and the like, work like telling time.

This is because we subtract out 12 after doing the addition. Because the number 16 is "reduced" to the number 4 in the above example, one can say that "16 is reduced modulo The RSA system multiplies one number called the base by itself a number of times and the product is then divided by a modulus. The number of times a base is multiplied by itself is called the exponent and the process is called modular exponent. So the plaintext M is regenerated using the formula, Cd mod n 4.

New, faster and better methods for factoring numbers are constantly being devised. Obviously the longer a number is the harder is to factor, and so the better the security of RSA. As theory and computers improve, large and large keys will have to be used. This will only become a problem if a new factoring technique emerges that requires keys of such lengths to be used that necessary key length increases much faster than the increasing average speed of computers utilizing the RSA algorithm.

RSA's future security relies solely on advances in factoring techniques. The individual steps are discussed in the following sub-sections. Speech Acquisition The recording of Bangla speech words was completed in a sound proof laboratory environment with the help of close-talking microphone, high quality sound card and sound recorder software. The five hundred Bangla words originated from six speakers were recorded as wav file to make a sample database.

The utterances were recorded at a sampling rate of 8. Pre-processing and Data Extraction To extract wave data, we first discard 58 bytes file header from the beginning of the wave file and then read wave data as character. The data extraction process extracts require voiced data from the input speech signal, which may contain silence, unvoice and voice.

This data are stored in a text file as integer data. This is usually done by detecting the proper start and end points of the speech events voicing and unvoicing and then separated into different pieces containing the audio signals on the basis of the detected start and end points [10], as shown in Figure Proper data extraction ensures better extraction of speech feature, which in turn results in better recognition accuracy.

The summary of the RSA algorithm is shown in the Figure Note that the factors p and q remain secret and n is public. Key Generation The system architecture for key generation is shown in Figure A random number generator generates bit pseudo random numbers and stores them in the rand FIFO. Once the FIFO is full, the random number generator stops working. The primality tester takes a random number as input and tests if it is a prime. Modular Exponentiation The modular exponentiation operation is simply an exponentiation operation where modular multiplication is intensively performed.

Here, it is only the reverse of Encryption. That code is converted to the original message and goes to the receiver. That is, the cipher text is converted to plain text. If you can catch the secret of this cipher text, you can claim yourself in as a hacker. Voltage Lab.