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[BinarySHOCK]

Added line numbers just so you don't have to count the lines

Code:

1 OPEN "file to encrypt" FOR BINARY AS #1
2 OPEN "output file" FOR BINARY AS #2
3 Code = 128
4 Bit = 1
5 WHILE NOT EOF(1)
6      A$ = " "
7      GET #1, , A$
8      B$ = CHR$(ASC(A$) XOR (Code AND 255))
9      PUT #2, , B$
10     Code = Code + (((((ASC(A$) + LOF(1)) AND 3)) * Bit))
11     Bit = Bit * 2
12     IF Bit = 128 THEN Bit = 1
13 WEND
14 CLOSE 1, 2