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Miscellany/Encrypt/!Crypt/!Help

This website contains an archive of files for the Acorn Electron, BBC Micro, Acorn Archimedes, Commodore 16 and Commodore 64 computers, which Dominic Ford has rescued from his private collection of floppy disks and cassettes.

Some of these files were originally commercial releases in the 1980s and 1990s, but they are now widely available online. I assume that copyright over them is no longer being asserted. If you own the copyright and would like files to be removed, please contact me.

Tape/disk: Home » Recent acquisitions » Acorn ADFS disks » adfs_AcornComputing_199402.adf » 9402
Filename: Miscellany/Encrypt/!Crypt/!Help
Read OK:
File size: 0539 bytes
Load address: 0000
Exec address: 0000
Duplicates

There is 1 duplicate copy of this file in the archive:

File contents
Crypt is a powerful desktop encryption utility. To start a session, load it up and click with select or adjust on the icon to input a password (The Default is 'Default'), remembering that the password is case sensitive.

 Now drag a file onto crypt and after a short pause, it will offer you the opportunity to name the encrypted version (in usual RiscOs style).When you want to decode it, simply drag the encoded version onto the icon, and the original file will be recovered as long as the password used during encryption is the same as the one currently inputted.

 Remember that once a file is encoded, it will not compress very well, so archive your data (if you can and you want) before using Crypt on the single archive file.

 If the passwords are different, an error will be generated (different CRCs), but even if some hacker removed this error, the resulting file would be garbage). 

 I will not go into detail about the encryption used, suffice to say that no pattern will be revealed if the original file contained large blank sections, and decoding of a file without knowing the password is an EXTREMELY difficult task, even if you know exactly how Crypt works (which is why I haven't bothered to hide the code) - my computer would take a trillion (10^12) years (maximum) to blindly try all possibilities on a 300k file.
00000000  0a 43 72 79 70 74 20 69  73 20 61 20 70 6f 77 65  |.Crypt is a powe|
00000010  72 66 75 6c 20 64 65 73  6b 74 6f 70 20 65 6e 63  |rful desktop enc|
00000020  72 79 70 74 69 6f 6e 20  75 74 69 6c 69 74 79 2e  |ryption utility.|
00000030  20 54 6f 20 73 74 61 72  74 20 61 20 73 65 73 73  | To start a sess|
00000040  69 6f 6e 2c 20 6c 6f 61  64 20 69 74 20 75 70 20  |ion, load it up |
00000050  61 6e 64 20 63 6c 69 63  6b 20 77 69 74 68 20 73  |and click with s|
00000060  65 6c 65 63 74 20 6f 72  20 61 64 6a 75 73 74 20  |elect or adjust |
00000070  6f 6e 20 74 68 65 20 69  63 6f 6e 20 74 6f 20 69  |on the icon to i|
00000080  6e 70 75 74 20 61 20 70  61 73 73 77 6f 72 64 20  |nput a password |
00000090  28 54 68 65 20 44 65 66  61 75 6c 74 20 69 73 20  |(The Default is |
000000a0  27 44 65 66 61 75 6c 74  27 29 2c 20 72 65 6d 65  |'Default'), reme|
000000b0  6d 62 65 72 69 6e 67 20  74 68 61 74 20 74 68 65  |mbering that the|
000000c0  20 70 61 73 73 77 6f 72  64 20 69 73 20 63 61 73  | password is cas|
000000d0  65 20 73 65 6e 73 69 74  69 76 65 2e 0a 0a 20 4e  |e sensitive... N|
000000e0  6f 77 20 64 72 61 67 20  61 20 66 69 6c 65 20 6f  |ow drag a file o|
000000f0  6e 74 6f 20 63 72 79 70  74 20 61 6e 64 20 61 66  |nto crypt and af|
00000100  74 65 72 20 61 20 73 68  6f 72 74 20 70 61 75 73  |ter a short paus|
00000110  65 2c 20 69 74 20 77 69  6c 6c 20 6f 66 66 65 72  |e, it will offer|
00000120  20 79 6f 75 20 74 68 65  20 6f 70 70 6f 72 74 75  | you the opportu|
00000130  6e 69 74 79 20 74 6f 20  6e 61 6d 65 20 74 68 65  |nity to name the|
00000140  20 65 6e 63 72 79 70 74  65 64 20 76 65 72 73 69  | encrypted versi|
00000150  6f 6e 20 28 69 6e 20 75  73 75 61 6c 20 52 69 73  |on (in usual Ris|
00000160  63 4f 73 20 73 74 79 6c  65 29 2e 57 68 65 6e 20  |cOs style).When |
00000170  79 6f 75 20 77 61 6e 74  20 74 6f 20 64 65 63 6f  |you want to deco|
00000180  64 65 20 69 74 2c 20 73  69 6d 70 6c 79 20 64 72  |de it, simply dr|
00000190  61 67 20 74 68 65 20 65  6e 63 6f 64 65 64 20 76  |ag the encoded v|
000001a0  65 72 73 69 6f 6e 20 6f  6e 74 6f 20 74 68 65 20  |ersion onto the |
000001b0  69 63 6f 6e 2c 20 61 6e  64 20 74 68 65 20 6f 72  |icon, and the or|
000001c0  69 67 69 6e 61 6c 20 66  69 6c 65 20 77 69 6c 6c  |iginal file will|
000001d0  20 62 65 20 72 65 63 6f  76 65 72 65 64 20 61 73  | be recovered as|
000001e0  20 6c 6f 6e 67 20 61 73  20 74 68 65 20 70 61 73  | long as the pas|
000001f0  73 77 6f 72 64 20 75 73  65 64 20 64 75 72 69 6e  |sword used durin|
00000200  67 20 65 6e 63 72 79 70  74 69 6f 6e 20 69 73 20  |g encryption is |
00000210  74 68 65 20 73 61 6d 65  20 61 73 20 74 68 65 20  |the same as the |
00000220  6f 6e 65 20 63 75 72 72  65 6e 74 6c 79 20 69 6e  |one currently in|
00000230  70 75 74 74 65 64 2e 0a  0a 20 52 65 6d 65 6d 62  |putted... Rememb|
00000240  65 72 20 74 68 61 74 20  6f 6e 63 65 20 61 20 66  |er that once a f|
00000250  69 6c 65 20 69 73 20 65  6e 63 6f 64 65 64 2c 20  |ile is encoded, |
00000260  69 74 20 77 69 6c 6c 20  6e 6f 74 20 63 6f 6d 70  |it will not comp|
00000270  72 65 73 73 20 76 65 72  79 20 77 65 6c 6c 2c 20  |ress very well, |
00000280  73 6f 20 61 72 63 68 69  76 65 20 79 6f 75 72 20  |so archive your |
00000290  64 61 74 61 20 28 69 66  20 79 6f 75 20 63 61 6e  |data (if you can|
000002a0  20 61 6e 64 20 79 6f 75  20 77 61 6e 74 29 20 62  | and you want) b|
000002b0  65 66 6f 72 65 20 75 73  69 6e 67 20 43 72 79 70  |efore using Cryp|
000002c0  74 20 6f 6e 20 74 68 65  20 73 69 6e 67 6c 65 20  |t on the single |
000002d0  61 72 63 68 69 76 65 20  66 69 6c 65 2e 0a 0a 20  |archive file... |
000002e0  49 66 20 74 68 65 20 70  61 73 73 77 6f 72 64 73  |If the passwords|
000002f0  20 61 72 65 20 64 69 66  66 65 72 65 6e 74 2c 20  | are different, |
00000300  61 6e 20 65 72 72 6f 72  20 77 69 6c 6c 20 62 65  |an error will be|
00000310  20 67 65 6e 65 72 61 74  65 64 20 28 64 69 66 66  | generated (diff|
00000320  65 72 65 6e 74 20 43 52  43 73 29 2c 20 62 75 74  |erent CRCs), but|
00000330  20 65 76 65 6e 20 69 66  20 73 6f 6d 65 20 68 61  | even if some ha|
00000340  63 6b 65 72 20 72 65 6d  6f 76 65 64 20 74 68 69  |cker removed thi|
00000350  73 20 65 72 72 6f 72 2c  20 74 68 65 20 72 65 73  |s error, the res|
00000360  75 6c 74 69 6e 67 20 66  69 6c 65 20 77 6f 75 6c  |ulting file woul|
00000370  64 20 62 65 20 67 61 72  62 61 67 65 29 2e 20 0a  |d be garbage). .|
00000380  0a 20 49 20 77 69 6c 6c  20 6e 6f 74 20 67 6f 20  |. I will not go |
00000390  69 6e 74 6f 20 64 65 74  61 69 6c 20 61 62 6f 75  |into detail abou|
000003a0  74 20 74 68 65 20 65 6e  63 72 79 70 74 69 6f 6e  |t the encryption|
000003b0  20 75 73 65 64 2c 20 73  75 66 66 69 63 65 20 74  | used, suffice t|
000003c0  6f 20 73 61 79 20 74 68  61 74 20 6e 6f 20 70 61  |o say that no pa|
000003d0  74 74 65 72 6e 20 77 69  6c 6c 20 62 65 20 72 65  |ttern will be re|
000003e0  76 65 61 6c 65 64 20 69  66 20 74 68 65 20 6f 72  |vealed if the or|
000003f0  69 67 69 6e 61 6c 20 66  69 6c 65 20 63 6f 6e 74  |iginal file cont|
00000400  61 69 6e 65 64 20 6c 61  72 67 65 20 62 6c 61 6e  |ained large blan|
00000410  6b 20 73 65 63 74 69 6f  6e 73 2c 20 61 6e 64 20  |k sections, and |
00000420  64 65 63 6f 64 69 6e 67  20 6f 66 20 61 20 66 69  |decoding of a fi|
00000430  6c 65 20 77 69 74 68 6f  75 74 20 6b 6e 6f 77 69  |le without knowi|
00000440  6e 67 20 74 68 65 20 70  61 73 73 77 6f 72 64 20  |ng the password |
00000450  69 73 20 61 6e 20 45 58  54 52 45 4d 45 4c 59 20  |is an EXTREMELY |
00000460  64 69 66 66 69 63 75 6c  74 20 74 61 73 6b 2c 20  |difficult task, |
00000470  65 76 65 6e 20 69 66 20  79 6f 75 20 6b 6e 6f 77  |even if you know|
00000480  20 65 78 61 63 74 6c 79  20 68 6f 77 20 43 72 79  | exactly how Cry|
00000490  70 74 20 77 6f 72 6b 73  20 28 77 68 69 63 68 20  |pt works (which |
000004a0  69 73 20 77 68 79 20 49  20 68 61 76 65 6e 27 74  |is why I haven't|
000004b0  20 62 6f 74 68 65 72 65  64 20 74 6f 20 68 69 64  | bothered to hid|
000004c0  65 20 74 68 65 20 63 6f  64 65 29 20 2d 20 6d 79  |e the code) - my|
000004d0  20 63 6f 6d 70 75 74 65  72 20 77 6f 75 6c 64 20  | computer would |
000004e0  74 61 6b 65 20 61 20 74  72 69 6c 6c 69 6f 6e 20  |take a trillion |
000004f0  28 31 30 5e 31 32 29 20  79 65 61 72 73 20 28 6d  |(10^12) years (m|
00000500  61 78 69 6d 75 6d 29 20  74 6f 20 62 6c 69 6e 64  |aximum) to blind|
00000510  6c 79 20 74 72 79 20 61  6c 6c 20 70 6f 73 73 69  |ly try all possi|
00000520  62 69 6c 69 74 69 65 73  20 6f 6e 20 61 20 33 30  |bilities on a 30|
00000530  30 6b 20 66 69 6c 65 2e  0a                       |0k file..|
00000539