diff --git a/requirements.txt b/requirements.txt
index 643f072..7e35ed2 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -5,4 +5,3 @@ opencv-python==4.7.0.72
 scikit-image==0.19.3
 scipy==1.9.3
 stl==0.0.3
-
diff --git a/src/main.py b/src/main.py
index 105aa96..447e862 100644
--- a/src/main.py
+++ b/src/main.py
@@ -8,6 +8,7 @@ import argparse as ap
 import sys
 import json
 from os.path import exists
+import hashlib
 
 # Libraries for image processing
 import numpy as np
@@ -18,7 +19,6 @@ from stl import mesh
 # Import custom image filter library
 import filters as flt
 
-
 class app:
     def __init__(self):
         # Parse arguments from command line
@@ -286,7 +286,7 @@ class app:
 
         plt.show()
         self.save_stl()
-        print(f"Saving model to ", self.stl_path, file=sys.stderr)
+        print(f"Saving model to ", self.stl_filename, file=sys.stderr)
 
     def prepare_heightmap(self):
         '''Modify image values to get usable height/depth values.
@@ -327,18 +327,70 @@ class app:
 
         self.meshgrid = np.meshgrid(x, y)
 
+    def write_stl_header(self):
+        '''Write stl header.
+        '''
+        
+        # Truncate if necessary
+        if (len(self.param_string) > 80):
+            self.param_string = self.param_string[:80]
+            print("Warning: Parameter string too long, truncating", file=sys.stderr)
+            
+        # Overwrite stl header (which is only 80 bytes)
+        print("Writing info to stl header", file=sys.stderr)
+        with open(self.stl_filename, "r+") as f:
+            f.write(self.param_string)
+
     def get_ID(self):
-        '''Get unique ID for the model.
-        Consists of pair input_file + preset_name.
+        '''Get unique ID for the model, used in filename and on the model backside.
+        Also create parameter string for stl header, which is used to create ID using hash function SHA512.
         '''
 
-        # TODO: somehow compress this to fit it onto the model
-        self.id = self.input_file.split("/")[-1].split(".")[0] + "_" + self.preset_name
-        # TODO: hash is not unique, find a better way
-        # TODO: stl file format has 80 chars for header, use that space to store info
-        # python generates a random value for security reasons, it has to be turned off
-        self.id = str(hash(self.id))
-        #print(self.id)
+        # these are the same for all types of models
+        param_list = [self.input_file, str(self.dpi)]
+
+        # add parameters specific to the model creation process
+        if self.args.config:
+            param_list.append(self.config_file)
+            param_list.append(self.preset_name)
+        else:
+            # add filters with their params
+            filter_list = []
+            for i in range(len(self.filters)):
+                tmp_params = []
+                for j in self.params[i+1]:
+                    if self.params[i+1][j] != None:
+                        tmp_params.append(str(j[:3] + ":" + str(self.params[i+1][j])))
+                tmp_params = ",".join(tmp_params)
+                tmp = str(self.filters[i][0:3])
+                if tmp_params != "":
+                    tmp = tmp + ";" + str(tmp_params)
+                filter_list.append(tmp)
+            filter_string = ">".join(filter_list)
+            param_list.append(filter_string)
+
+        # these are the same for all types of models
+        param_list.append(str(self.height_line))
+        param_list.append(str(self.height_base))
+
+        # add parameters specific to the model type
+        if self.mode == "curved":
+            param_list.append(str(self.curv_rate_x))
+            param_list.append(str(self.curv_rate_y))
+
+        if self.mode == "planar":
+            param_list.append("P")
+        
+        if self.args.mirror:
+            param_list.append("M")
+
+        # string that will later be put inside the header of an stl file
+        self.param_string = "\\".join(param_list) + "\n"
+        
+        # hash the param string to get unique ID, this will be put in filename and on the back of the model
+        # not using built-in hash function because it's seed cannot be set to constant number
+        # don't need to worry about collisions and security, just need a relatively unique ID
+        self.id = str(hashlib.sha512(self.param_string.encode('utf-8')).hexdigest())[:10]
 
     def append_faces(self, faces, c):
         # Function to add faces to the list
@@ -501,7 +553,7 @@ class app:
             count = self.append_faces(faces, count)
 
         self.create_stl_mesh(faces, vertices)
-
+       
     def make_stl_curved(self):
         '''Map fingerprint to finger model.
         '''
@@ -612,18 +664,10 @@ class app:
         '''Save final mesh to stl file.
         '''
 
-        # TODO: add a hash function to create ID specific to
-        # input image + preset from config. file or from console + input params
-        # TODO: add the full parameters and filters to a file inside output dir.
-        # TODO: somehow add the full params to the stl file header if possible.
-        # TODO: add the ID to backplate 
-        # TODO: add the ID to stl file name
-
-        # for now only path + id(input filename + preset name) + .stl is used
-        # TODO: add output filename to the filename, hash the ID
-        # stl_filename = self.stl_path.rsplit("/")[0] + self.output_file.split("/"))[-1] + "_" + self.id + ".stl"
-        stl_filename = self.output_file.split(".")[0] + "_" + self.id + ".stl"
-        self.stl_model.save(stl_filename)
+        # create output file name, save it and write header with file info
+        self.stl_filename = self.output_file.split(".")[0] + "_" + self.id + ".stl"
+        self.stl_model.save(self.stl_filename)
+        self.write_stl_header()
 
 
 # run the application