Preliminary high level SP-IBBE

Author: stefan-contiu

sp-ibbe.py

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+'''
+  Implementation of SP-IBBE,
+  i.e. Secured & Partitioned - Identity Based Broadcast Encryption.
+
+  Author: Stefan Contiu <[email protected]>
+
+  Published under Apache v2 License:
+        https://www.apache.org/licenses/LICENSE-2.0.txt
+
+  Remark(s):
+        This file holds high level operations of the SP-IBBE scheme.
+        The administrators have a HONEST-BUT-CURIOUS trust model, meaning they
+        will execute what is asked from them but without confidentiality
+        guarantees.
+'''
+
+import numpy as np
+
+MAX_USERS_PER_PARTITION = 1000
+
+
+def add_user_to_group(user_name, group_name):
+    # 1. get partition id
+    partition_id = compute_partition_id(user_name, group_name)
+
+    # 2. get [Members List] and [C1, C2]
+    members = []
+    g_meta = []
+
+    # 3. append new member
+    members.append(user_name)
+
+    # 4. modify C2
+
+    # 5. get a signed hash of new data
+
+    # 6. push to cloud
+
+    pass
+
+def remove_user_from_group(user_name, group_name):
+    pass
+
+def compute_partition_id(user_name, group_name):
+    gp = GroupPartitionsMeta()
+
+    # do we need more partitions for the group ?
+    current_free_space = gp.get_remaining_space(group_name);
+    if (current_free_space < free_space_treshold):
+        # add some more partitions
+
+    # weighted sampling
+    partitions = range(partitions_count)
+    weights = gp.group_free_space_histogram(group_name)
+    i = np.random.choice(vec,size=1,replace=False, p=partitions)
+
+    return group_name + "_" + i
+
+class GroupPartitionsMeta:
+
+    group_free_space = dict()
+
+    user_partitions = dict()
+
+    group_partitions_count = dict()
+
+    def __init__(self, arg):
+        pass
+
+    def get_remaining_space(self, group):
+        # if group_free_space does not have group, create partition table
+        return group_free_space[group]
+
+    def add_partitions(self, group_name, new_partitions_count):
+        # add
+
+    def group_free_space_histogram(self, group_name):
+        # todo this method should be modified to return percents
+        return group_partitions_count[group_name]
+
+def main():
+    generate_partition_id("[email protected]", "friends")
+
+if __name__ == "__main__":
+    main()