A pseudo_encrypt function implementation for int and bigint

pseudo_encrypt.sql

CREATE OR REPLACE FUNCTION pseudo_encrypt(value int) returns int AS $$
DECLARE
l1 int;
l2 int;
r1 int;
r2 int;
i int:=0;
BEGIN
 l1:= (value >> 16) & 65535;
 r1:= value & 65535;
 WHILE i < 3 LOOP
   l2 := r1;
   r2 := l1 # ((((1366 * r1 + 150889) % 714025) / 714025.0) * 32767)::int;
   l1 := l2;
   r1 := r2;
   i := i + 1;
 END LOOP;
 return ((r1 << 16) + l1);
END;
$$ LANGUAGE plpgsql strict immutable;

pseudo_encrypt_bigint.sql

-- https://stackoverflow.com/a/12761795/2026325
CREATE OR REPLACE FUNCTION pseudo_encrypt(VALUE bigint) returns bigint AS $$
DECLARE
l1 bigint;
l2 bigint;
r1 bigint;
r2 bigint;
i int:=0;
BEGIN
    l1:= (VALUE >> 32) & 4294967295::bigint;
    r1:= VALUE & 4294967295;
    WHILE i < 3 LOOP
        l2 := r1;
        r2 := l1 # ((((1366.0 * r1 + 150889) % 714025) / 714025.0) * 32767*32767)::int;
        l1 := l2;
        r1 := r2;
        i := i + 1;
    END LOOP;
RETURN ((l1::bigint << 32) + r1);
END;
$$ LANGUAGE plpgsql strict immutable;

A random id generator

CREATE SEQUENCE global_id_sequence;
CREATE 
OR REPLACE FUNCTION id_generator(OUT result bigint) AS $$ 
DECLARE our_epoch bigint := 1314220021721;
seq_id bigint;
now_millis bigint;
-- the id of this DB shard, must be set for each     
-- schema shard you have - you could pass this as a parameter too     
shard_id int := 1;
BEGIN 
SELECT 
  nextval('global_id_sequence') % 1024 INTO seq_id;
SELECT 
  FLOOR(
    EXTRACT(
      EPOCH 
      FROM 
        clock_timestamp()
    ) * 1000
  ) INTO now_millis;
result := (now_millis - our_epoch) << 23;
result := result | (shard_id << 10);
result := result | (seq_id);
END;
$$ LANGUAGE PLPGSQL;