_ I want to anonymize the sensitive data of my table with procedure PL SQL.
_ For this I created a procedure that browses the sensitive data of my table by applying a hash to the data each time.
_ But I want to get a hashed value which the same size as the old value.
_ So I use the substr() function to cut the hashed value to keep the same size.
_ I have a problem with the splitting of the hashed string for the first value.
for example
the first value
_ Code bic: ‘??Oh?z+h5?????0?’
_ After hashing
_ ‘?Oh?z’

_ I should have ‘?Oh’ instead of ‘?Oh?z’

the rest of the result is correct

_ ‘U??Ei???l?ve?<C\n”?’
_ After SUBSTR
_ ‘U??’

here is my source code

create or replace procedure anonymize 
IS
bic_p  varchar(100);
CURSOR c_cursor is select bic from banc;
bic_h raw(15);

BEGIN
 
open c_cursor;

loop
    fetch c_cursor into bic_p;
    exit when c_cursor%notfound;
   dbms_output.put_line('bic: ' || UTL_I18N.RAW_TO_CHAR (dbms_crypto.hash(
            utl_i18n.string_to_raw(bic_p, 'AL32UTF8'),
            dbms_crypto.hash_sh1
          ), 'AL32UTF8'));
    
  dbms_output.put_line('After SUBSTR');
    
    bic_p := SUBSTR(UTL_I18N.RAW_TO_CHAR (dbms_crypto.hash(
            utl_i18n.string_to_raw(bic_p, 'AL32UTF8'),
            dbms_crypto.hash_sh1
          ), 'AL32UTF8'),
          1,3);
          
    dbms_output.put_line('bic: ' || bic_p);

end loop;

END anonymize;