Amazing-Python-Scripts

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import math
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import random
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# Arguments provide range to generate two prime numbers
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def primenumbers(srt, n):
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    primenos = []
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    prime = [True for i in range(n + 2 - srt)]
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    prime[0] = False
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    prime[1] = False
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    for p in range(srt, int(math.sqrt(n)) + 1):
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        if prime[p] == True:
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            for i in range(p * p, n + 1, p):
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                prime[i] = False
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    for p in range(srt, n + 1):
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        if prime[p]:
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            primenos.append(p)
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    P = random.choice(primenos)
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    primenos.remove(P)
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    Q = random.choice(primenos)
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    return (P, Q)
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# RSA Algorithm Implementation:
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print("RSA Implementation starts for the connection")
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for c in range(5):
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    print("------")
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p, q = primenumbers(1, 30)
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N = p * q
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f = (p - 1) * (q - 1)
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# Generate Public Key for Encryption
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def publickey():
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    for i in range(2, f):
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        if math.gcd(f, i) == 1:
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            E = i
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            break
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    return E
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E = publickey()
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def privatekey():
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    for j in range(1, N):
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        if math.fmod((E * j), (f)) == 1:
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            # if (E * j) % (f) == 1:
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            D = j
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            break
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    return D
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D = privatekey()
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print("Generated Public Key for Encryption E: ", E)
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print("Generated Private Key for Decryption D: ", D)
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Plain_text = float(input("Enter Plain text in numerical data type: \n"))
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x = math.pow(Plain_text, E)
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Cipher_text = math.fmod(x, N)
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print("Generated Cipher Text using Public Key: ", Cipher_text)
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D_user = int(input("Enter your private key for Decryption \n"))
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if D_user == D:
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    y = math.pow(Cipher_text, D)
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    Decrypted_text = math.fmod(y, N)
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    print("The Cipher Text has been decrypted: ", Plain_text)
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else:
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    print("ENTERED WRONG PRIVATE KEY")
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