#1




Idenitfying a cryptographic algorithm
I need help identifying this decryption algorithm, the argument "s" in the function d3 is the encrypted string.
If this is a known algorithm, I would like to get the algorithm to write the encrypted string "s" myslef. Code:
function d3(s) { var _loc4_ = s.substr(0,11); var _loc9_ = Number(_loc4_.substr(10,1)); var _loc3_ = Number(_loc4_.substr(_loc9_,2)); var _loc7_ = s.substr(22,_loc3_); var _loc10_ = String(s.substr(11,11)); var _loc8_ = Number(s.substr(21,1)); var _loc6_ = Number(s.substr(11 + _loc8_,2)); var _loc5_ = s.substr(22 + _loc3_,s.length  (22 + _loc3_)); return this.d(_loc7_,_loc6_,_loc5_); } function d(a, k, s) { return this.t(a, k,s); } function t(a, k, s) { var _loc8_ = undefined; var _loc3_ = ""; var _loc4_ = s.length; var _loc2_ = 0; while(_loc2_ < _loc4_) { _loc3_ = _loc3_ + this.r(a,s.charAt(_loc2_),k); _loc2_ = _loc2_ + 1; } return _loc3_; } function r(a, c, k) { var _loc2_ = a.indexOf(c); var _loc1_ = a.length; if(_loc2_ != 1) { return a.charAt((_loc2_ + k + _loc1_) % _loc1_); } return c; } 
#2




I think if you rewrote and cleaned up that code, it would be easier. It appears not as a much of a cryptographic algorithm as some simple string manipulation code. It can be a single function with a loop having a single condition inside of it. After cleaning it up, figuring out how to invert the function should be somewhat straight forward.

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niculaita (07162020) 
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