OneTimePadInstructions.txt

@@ -0,0 +1,31 @@
+Specification for one time pad use.
+
+One Time Pad must be smaller than 4Gb!
+
+File format for transmission data (cyphertext):
+Part 1 - 32 bits, indicating the address of the start bit.
+Part 2 - The message, no minimum length imposed.
+
+Message input format: Ascii text (for starters)
+
+File extension to be used .bin
+
+To ensure security, the USB stick must be connected for less than 20 minutes at any time.
+This prevents the contents being copied, as it's rather slow!
+
+Encryption process:
+1) Scan the OTP for the first 1 (binary value >0). This is the start location.
+2) Encode the start location in the first 32bits of the output file.
+3) Bitwise XOR the message with the OTP to produce the cyphertext.
+4) Erase all bits used in the OTP, setting to 0.
+5) Output file contains 32 bits of start address and the cyphertext.
+6) Erase the original message by writing all bits to 0.
+
+Decryption Process:
+1) Read the first 32 bits of the cyphertext to obtain position P.
+2) Go to P within the OTP.
+3) XOR the data from bits 33 onwards of the cyhertext with position P > of the OTP.
+4) Erase all bits used in the OTP, setting to 0.
+5) Output file contains only the decrypted cyphertext.  
+6) Display the output file for reading.
+7) Erase the output file after reading by writing all bits to 0.