Md. Ariful HoqueRoll No: MSc 140202Discipline : CSEKhulna University
Data communication.
Vital role of Cryptography.
Phone communication.
E-commerce.
Pay-TV.
Transmitting financial information.
Video Conferencing.
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Cryptosystem.Encryption
Decryption
Symmetric cryptosystem.
RSA cryptographic algorithm.
Uses a pair of related keys -Private key
Public key
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Record 500 Bangla speech words.
Extract data.
Stored in a text file as integer data.
Encrypt and decrypt.
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Speech Word
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Recording of Bangla speech words.
Recorded as wav file.
Sampling rate 8.00 KHz.
Coded in 8 bits PCM.
Speech Word
Preprocessing and Data Extraction
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Discard 58 bytes from beginning.
Extract require voiced data.
Contain silence, unvoiced and voice.
Stored in a text file.
Speech Word
Preprocessing and Data Extraction
Public key {e, n}
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Speech Word
Preprocessing and Data Extraction
Encryption Process
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Public key {e, n}
Speech Word
Preprocessing and Data Extraction
Encryption Process
Private key {d, n}
Public key {e, n}
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Speech Word
Preprocessing and Data Extraction
Encryption Process
Decryption Process
Public key {e, n}
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Private key {d, n}
Speech Word
Preprocessing and Data Extraction
Encryption Process
Decryption Process
Original Speech Word
Private key {d, n}
Public key {e, n}
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Random Number Generator
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Random Number Generator
Rand FIFO
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Random Number Generator
Rand FIFO
PrimalityTester
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Random Number Generator
Rand FIFO
PrimalityTester
Prime FIFO
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Random Number Generator
Rand FIFO
PrimalityTester
Prime FIFO
N=p*q∅(n)=(p-1)(q-1)
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Random Number Generator
Rand FIFO
PrimalityTester
Prime FIFO
N=p*q∅(n)=(p-1)(q-1)
n
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Random Number Generator
Rand FIFO
PrimalityTester
Prime FIFO
N=p*q∅(n)=(p-1)(q-1)
gcd(e, ∅(n))=11<e< ∅(n)
n
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Random Number Generator
Rand FIFO
PrimalityTester
Prime FIFO
N=p*q∅(n)=(p-1)(q-1)
gcd(e, ∅(n))=11<e< ∅(n)
e n
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Random Number Generator
Rand FIFO
PrimalityTester
Prime FIFO
N=p*q∅(n)=(p-1)(q-1)
gcd(e, ∅(n))=11<e< ∅(n)
e.d =1mod ∅(n0 ≤d ≤n
e n
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Random Number Generator
Rand FIFO
PrimalityTester
Prime FIFO
N=p*q∅(n)=(p-1)(q-1)
gcd(e, ∅(n))=11<e< ∅(n)
e.d =1mod ∅(n0 ≤d ≤n
d e n
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e n Public key
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d
e n
n
Public key
Private key
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M
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M
e
n
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M
e
n
Modular Exponentiation Me mod n
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M
e
n
CModular Exponentiation Me mod n
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C
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C
d
n
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C
d
n
Modular Exponentiation Cd mod n
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C
d
n
MModular Exponentiation Cd mod n
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Input: A, B, n Output: E = AB mod n
LR binary method
E <= 1; for i = k-1 to 0
If Bi =1E <= A*E mod nend if
if i ≠ 0 E <= E*E mod n; end if
end for return E;
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Objective.
500 speech words recorded.
Saved as .wav format.
Extracted integer data.
Taken txt file as input.
Produce unreadable message.
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RSA algorithm used to encrypt and decrypt.
M lies in the range .
Encrypt 500 word at a time.
Limitations.
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Thanks To All
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