1. Code Obfuscation Its limits in today Software & Hardware By Shahid Razzaq

2. What is this Obfuscation? • Literal Meaning of Obfuscation: • The word ‘obfuscation' refers to the concept of concealing the meaning of communication by making it more confusing and harder to interpret. • Code Obfuscation: • Code obfuscation is the generation or alteration of source code and/or object code in such a way that it is easy for the computer to comprehend but considerably difficult to reverse engineer.

3. Reverse Engineering Code • Normal Engineering: Dude writes code -> Dude compiles -> Dude parties with the binary • Reverse Engineering:Evil dude gets the binary -> Uses powerful tools (e.g IDA Pro) to gain knowledge about program -> Gets to know code structure, control flow, and valuable assets, keys, alrogithms, PI • IDA Pro: How much can it do?

7. How can Obfuscation Help • Types of Obfuscation: • Code Structure Obfuscation • Data Obfuscation • Control Obfuscation • Preventive Obfuscation • Effects of Obfuscation on Code: • Code logic doesn’t change • Decreases footprint of code • Decreases performance (w.r.t time) • Harder for developers during product cycle & possibly support

8. Obfuscation in Action • Widely used in Intermediate Compiled Languages .Net, Java • Dotfuscator (.Net, Microsoft Visual Studio) • ProGuard (Java, free) • Factor that prevent use of Obfuscation • Cost of Obfuscation • Execution time of code • High Program complexity

9. Limits to Obfuscation • No obfuscation enough against extremely dedicated hackers • Prevents against easy reverse engineering using tools • How can Software Help: • Built-in support in OS • Public APIs • Hardware Assisted Obfuscation: • Use of hardware for decryption • How are decryption keys transferred?

10. Obfuscation in Future • Interesting Scenario: ‘Brain’ obfuscation • Processor detached from memory • Non conventional use of processor registers • Memory kept relatively in-accessable, encrypted • Obfuscation in design, like a real brain. Example?

11. What does this do? #include <stdio.h> main(t,_,a)char *a;{return!0<t?t<3?main(-79,-13,a+main(-87,1-_,main(-86,0,a+1)+a)):1,t<_?main(t+1,_,a):3,main(-94,-27+t,a)&&t==2?_<13?main(2,_+1,"%s %d %d\n"):9:16:t<0?t<-72?main(_,t,"@n'+,#'/*{}w+/w#cdnr/+,{}r/*de}+,/*{*+,/w{%+,/w#q#n+,/#{l,+,/n{n+,/+#n+,/#\;#q#n+,/+k#;*+,/'r :'d*'3,}{w+K w'K:'+}e#';dq#'l \q#'+d'K#!/+k#;q#'r}eKK#}w'r}eKK{nl]'/#;#q#n'){)#}w'){){nl]'/+#n';d}rw' i;# \){nl]!/n{n#'; r{#w'r nc{nl]'/#{l,+'K {rw' iK{;[{nl]'/w#q#n'wk nw' \iwk{KK{nl]!/w{%'l##w#' i; :{nl]'/*{q#'ld;r'}{nlwb!/*de}'c \;;{nl'-{}rw]'/+,}##'*}#nc,',#nw]'/+kd'+e}+;#'rdq#w! nr'/ ') }+}{rl#'{n' ')# \}'+}##(!!/"):t<-50?_==*a?putchar(31[a]):main(-65,_,a+1):main((*a=='/')+t,_,a+1) :0<t?main(2,2,"%s"):*a=='/'||main(0,main(-61,*a,"!ek;dc i@bK'(q)-[w]*%n+r3#l,{}:\nuwloca-O;m .vpbks,fxntdCeghiry"),a+1);}

12. Q & A