diff --git a/pySim/esim/saip/param_source.py b/pySim/esim/saip/param_source.py
index fb6151ea..87842619 100644
--- a/pySim/esim/saip/param_source.py
+++ b/pySim/esim/saip/param_source.py
@@ -18,6 +18,7 @@
 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
 
 import random
+import re
 from pySim.utils import all_subclasses_of
 
 class ParamSourceExn(Exception):
@@ -70,7 +71,28 @@ class ConstantSource(ParamSource):
     def get_next(self, csv_row:dict=None):
         return self.val
 
-class RandomDigitSource(ParamSource):
+class InputExpandingParamSource(ParamSource):
+
+    @classmethod
+    def expand_str(cls, s:str):
+        # user convenience syntax '0*32' becomes '00000000000000000000000000000000'
+        if '*' not in s:
+            return s
+        tokens = re.split(r"([^ \t]+)[ \t]*\*[ \t]*([0-9]+)", s)
+        if len(tokens) < 3:
+            return s
+        parts = []
+        for unchanged, snippet, repeat_str in zip(tokens[0::3], tokens[1::3], tokens[2::3]):
+            parts.append(unchanged)
+            repeat = int(repeat_str)
+            parts.append(snippet * repeat)
+        return ''.join(parts)
+
+    @classmethod
+    def from_str(cls, s:str):
+        return cls(cls.expand_str(s))
+
+class RandomDigitSource(InputExpandingParamSource):
     'return a different sequence of random decimal digits each'
     is_abstract = False
     name = 'random decimal digits'
@@ -100,6 +122,8 @@ class RandomDigitSource(ParamSource):
 
     @classmethod
     def from_str(cls, s:str):
+        s = cls.expand_str(s)
+
         if '..' in s:
             first_str, last_str = s.split('..')
             first_str = first_str.strip()
@@ -112,7 +136,7 @@ class RandomDigitSource(ParamSource):
         last_value = int(last_str) if last_str is not None else '9' * len(first_str)
         return cls(num_digits=len(first_str), first_value=first_value, last_value=last_value)
 
-class RandomHexDigitSource(ParamSource):
+class RandomHexDigitSource(InputExpandingParamSource):
     'return a different sequence of random hexadecimal digits each'
     is_abstract = False
     name = 'random hexadecimal digits'
@@ -133,6 +157,7 @@ class RandomHexDigitSource(ParamSource):
 
     @classmethod
     def from_str(cls, s:str):
+        s = cls.expand_str(s)
         return cls(num_digits=len(s.strip()))
 
 class IncDigitSource(RandomDigitSource):
diff --git a/pySim/esim/saip/personalization.py b/pySim/esim/saip/personalization.py
index 89c272cc..619f3819 100644
--- a/pySim/esim/saip/personalization.py
+++ b/pySim/esim/saip/personalization.py
@@ -430,7 +430,7 @@ class Iccid(DecimalParam):
     name = 'ICCID'
     min_len = 18
     max_len = 20
-    default_value = '0' * 18
+    default_value = '0*18'
     default_source = param_source.IncDigitSource
 
     @classmethod
@@ -581,7 +581,7 @@ class SdKey(BinaryParam):
 class SdKeyAes(SdKey):
     key_type = KeyType.aes
     allow_len = (16,24,32)
-    default_value = '00' * 32
+    default_value = '00*32'
 
 
 class SdKeyScp80(SdKeyAes):
@@ -873,7 +873,7 @@ class Puk(DecimalHexParam):
     allow_len = 8
     rpad = 16
     keyReference = None
-    default_value = '0' * allow_len
+    default_value = f'0*{allow_len}'
     default_source = param_source.RandomDigitSource
 
     @classmethod
@@ -911,7 +911,7 @@ class Pin(DecimalHexParam):
     rpad = 16
     min_len = 4
     max_len = 8
-    default_value = '0' * max_len
+    default_value = f'0*{max_len}'
     default_source = param_source.RandomDigitSource
     keyReference = None
 
@@ -952,7 +952,7 @@ class Pin(DecimalHexParam):
 class Pin1(Pin):
     is_abstract = False
     name = 'PIN1'
-    default_value = '0' * 4  # PIN are usually 4 digits
+    default_value = '0*4'  # PIN are usually 4 digits
     keyReference = 0x01
 
 class Pin2(Pin1):
@@ -1057,7 +1057,7 @@ class K(BinaryParam, AlgoConfig):
     name = 'K'
     algo_config_key = 'key'
     allow_len = int(128/8) # length in bytes (from BinaryParam)
-    default_value = '00' * allow_len
+    default_value = f'00*{allow_len}'
     default_source = param_source.RandomHexDigitSource
 
 class Opc(K):