Bornomala-Symmetric-Key (BSK) Stream Cipher

Key Generation • Encryption • Decryption • Advantages •

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Key Generation

Requirement:

• A strong key is required, a minimum of 8 characters
• Key must have to contain uppercase, lowercase, and digits.
• No Space is allowed in a key

Generated-Key is similar with hashing
Unless fixed length hashing, the generated key is of any size depanding on inputs message [variable-length hashing]

Key Generation Process
Roughly divided into three sections:

• Key Enhancement
• Key Substitution
• Random-indexing shuffle

Example:

Let's assume:

Initial Key (K) = HstU@5200
Message (M) = Hajee DanesH 26/10/19

Then:

Enhanced Key = HstU@5200HstU@5200Hst
Substitute Key = 6u,b.X(V'(g}T JyHxyYo
R-I Shuffle = ,(V6T.xu 'boyXH}ygYJ(

Final Key:

,(V6T.xu 'boyXH}ygYJ(

Encryption

With generated key and plaintext, the encryption process started. It can divided into two parts:

• Base-Format Encryption
• Padding
  

Padding is done in 5 steps:

• Format length of encrypted string (C)
• Format length of generated key (K)
• Key-triggered-reversible-shuffle
• Hexadecimal-conversion
• Randomizing with CC and EA characters

Example:

We got:

Generated Key (K) (21) = ,(V6T.xu 'boyXH}ygYJ(
Message (M) (21) = Hajee DanesH 26/10/19

Then:

Base-Format Encryption (C) (21) = t+b=[N^x0.wY;, NL9*{a

Padding:

Format length of encrypted string (C) (24) = t+b=[N^x0.wY;, NL9*{a~~~
Format length of generated key (K) (24) = ,(V6T.xu 'boyXH}ygYJ(,(V
Key-triggered-reversible shuffle (C) = ~,t~~L=a0Y{N[+w.;x9b^*N
Hexadecimal-conversion = 7E2C747E7E4C3D6130597B4E5B2B772E3B7839625E2A4E20
Randomizing with CC and EA = 082C7498034C3D6130597B4E5B2B772E3B7839625E2A4E20

Final Encrypted Result:

082C7498034C3D6130597B4E5B2B772E3B7839625E2A4E20

Decryption

Decryption process divides in two parts:

• Normalizing of Encrypted String (C)
• Decryption in Base-Format (M)

Key Generation is always the first step in both Encryption and Decryption.

Normalizing of encrypted string is done with 5 steps:

• Character seperation of CC and EA
• Base conversion (C)
• Format generated key (K)
• Key-Triggered-reversible shuffle
• Fix Length of encrypted string

Example:

We got:

Generated Key (K) (21) = ,(V6T.xu 'boyXH}ygYJ(
Ciphertext (C) (24) = 082C7498034C3D6130597B4E5B2B772E3B7839625E2A4E20

Decryption:

Character seperation of CC and EA = 7E2C747E7E4C3D6130597B4E5B2B772E3B7839625E2A4E20
Base conversion (C) = ~,t~~L=a0Y{N[+w.;x9b^*N
Format generated key (K) = ,(V6T.xu 'boyXH}ygYJ(,(V
Key-triggered-reversible shuffle (C) (24) = t+b=[N^x0.wY;, NL9*{a~~~
Fix length (C) (21) = t+b=[N^x0.wY;, NL9*{a
Decryption in base-format (M) = Hajee DanesH 26/10/19

Final Decrypted Result:

Hajee DanesH 26/10/19

Advantages

• Key used in this process meets standard password requirements
• Slightest change of the key results a completely different encrypted string
• Encrypted string is in hexadecimal format ranges from ASCII 0-255
• Encrypted string is a multiplication of 16 in hex.
• RSA encryption is a way of key-distribution of BSK cipher. Thus removes the drawbacks of symmetric-key cipher.

©️Sazzad-Saju

END OF DOCUMENT 😄