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defcon
- 1. http://www. elcomsoft .com Presentation on on DEF CON Nine, July 13 th - 15 th , 2001 Alexis Park in Las Vegas, Nevada USA eBooks security - theory and practice
- 2. eBooks security - theory and practice 1. Foreword 2. PDF encryption 3. Standard security handler 4. Rot13 handler 5. FileOpen handler 6. SoftLock handler 7. Adobe Web Buy handler (PDF Merchant) 8. Acrobat eBook Reader EBX handler (formerly GlassBook) http://www. elcomsoft .com 9. Arbitrary handler (obtaining encryption key from PDF viewer) 10. Security flaw in Acrobat plug-ins certification
- 5. eBook Pro compiler Short description (taken from www. ebookpro .com ) "eBook Pro", the only software in the universe that makes your information virtually 100% burglarproof! It comes with a lifetime, money-back guarantee "At Last, You Can Sell Information Online (And Make Thousands Of Sales Per Day) - Without The Danger Of Having Your Information Stolen And Resold By Others» http://www. elcomsoft .com Related Internet resources: http://www. ebookpro .com/ Actual features All HTML pages and supplementary files are compressed with deflate algorithm from ZLIB Compressed data are encrypted by XOR-ing each byte with every byte of the string “encrypted”, which is the same as XOR with constant byte
- 6. PDF file structure http://www. elcomsoft .com Related Internet resources: http://www.adobe.com/products/acrobat/ adobepdf .html Basic data types Example Boolean true Numeric 3.1415926 Object reference 23 0 R Name /ProcSet String (Contents) * Stream {binary data} * * - data could be encrypted <PDF file> ::= <header> <body> <cross-reference table> <trailer> <body> ::= <object> {<object>} <object> :: <objectID> (<data> | <stream dictionary> <stream>) Complex data types Example Array [23 0 R /XYZ null] Dictionary <</Name1 (Val1) /Name2 /Val2>>
- 7. PDF file encryption PDF Document <Encrypted Content> <<Encryption Dictionary>> Contains security handler name and supplementary information necessary to obtain encryption key http://www. elcomsoft .com Security handler Takes information from Encryption Dictionary , calculates document encryption key and passes it to PDF Viewer PDF Viewer Takes document encryption key , decrypts PDF document and display it on the screen Screen Related Internet resources: http://www.adobe.com/products/acrobat/ adobepdf .html
- 8. Object encryption key calculation Document encryption key http://www. elcomsoft .com Object ID + Generation MD5 HASH algorithm Object encryption key Document encryption key Scrambled Object ID + Generation MD5 HASH algorithm Object encryption key ‘ sAlT’ string Algorithm ver.1,2 Algorithm ver.3 Related Internet resources: http://www.adobe.com/products/acrobat/ adobepdf .html
- 10. Standard security handler http://www. elcomsoft .com Related Internet resources: http://www. elcomsoft .com/ apdfpr .html Time necessary for complete key enumeration (40 bits key) on PIII-450 Passwords per second on 450MHz Pentium III 15 hr 30 hr 60 hr 120 hr 240 hr 4 20 hr 40 hr 80 hr 160 hr 320 hr 3 30 hr 60 hr 120 hr 240 hr 480 hr 2 60 hr 120 hr 240 hr 480 hr 960 hr 1 512 GB 384 GB 256 GB 128 GB 0 GB PCs total HDD 1,610 102 MD5 + 40 RC4 3,250 51 MD5 + 20 RC4 Standard security handler 3 100,000 2 MD5 + 2 RC4 190,000 1 MD5 + 1 RC4 Standard security handler 2 Owner User Handler type P assword type
- 16. Adobe’s Acrobat eBookReader (formerly GlassBook) http://www. elcomsoft .com Related Internet resources: http://www.adobe.com/products/ contentserver /main.html Interim key calculation from hardware IDs CPU ID+ Volume ID SHA1 mor.dat file son.dat file Voucher RC5 Decrypt RSA Decrypt Private RSA key Document key Interim key Interim key RC5 Decrypt Fixed key Interim key Interim key calculation from hidden copy Document key calculation
- 17. Object encryption key calculation Document encryption key http://www. elcomsoft .com Object ID + Generation MD5 HASH algorithm Object encryption key Document encryption key Scrambled Object ID + Generation MD5 HASH algorithm Object encryption key ‘ sAlT’ string Algorithm ver.1,2 Algorithm ver.3 Related Internet resources: http://www.adobe.com/products/acrobat/ adobepdf .html
- 20. http://www. elcomsoft .com Presentation on on DEF CON Nine, July 13 th - 15 th , 2001 Alexis Park in Las Vegas, Nevada USA eBooks security - theory and practice