diff --git a/crypto.py b/bigchaindb/common/crypto.py
similarity index 100%
rename from crypto.py
rename to bigchaindb/common/crypto.py
diff --git a/exceptions.py b/bigchaindb/common/exceptions.py
similarity index 100%
rename from exceptions.py
rename to bigchaindb/common/exceptions.py
diff --git a/transaction.py b/bigchaindb/common/transaction.py
similarity index 100%
rename from transaction.py
rename to bigchaindb/common/transaction.py
diff --git a/util.py b/bigchaindb/common/util.py
similarity index 100%
rename from util.py
rename to bigchaindb/common/util.py