diff --git a/invokeai/app/services/model_install/model_install_default.py b/invokeai/app/services/model_install/model_install_default.py
index f522282fee..51c4878709 100644
--- a/invokeai/app/services/model_install/model_install_default.py
+++ b/invokeai/app/services/model_install/model_install_default.py
@@ -7,7 +7,6 @@ import time
 from hashlib import sha256
 from pathlib import Path
 from queue import Empty, Queue
-from random import randbytes
 from shutil import copyfile, copytree, move, rmtree
 from tempfile import mkdtemp
 from typing import Any, Dict, List, Optional, Set, Union
@@ -526,9 +525,6 @@ class ModelInstallService(ModelInstallServiceBase):
                 setattr(info, key, value)
         return info
 
-    def _create_key(self) -> str:
-        return sha256(randbytes(100)).hexdigest()[0:32]
-
     def _register(
         self, model_path: Path, config: Optional[Dict[str, Any]] = None, info: Optional[AnyModelConfig] = None
     ) -> str:
@@ -536,6 +532,10 @@ class ModelInstallService(ModelInstallServiceBase):
         # in which case the key field should have been populated by the caller (e.g. in `install_path`).
         config["key"] = config.get("key", self._create_key())
         info = info or ModelProbe.probe(model_path, config)
+        override_key: Optional[str] = config.get("key") if config else None
+
+        assert info.original_hash  # always assigned by probe()
+        info.key = override_key or info.original_hash
 
         model_path = model_path.absolute()
         if model_path.is_relative_to(self.app_config.models_path):
diff --git a/invokeai/app/services/shared/sqlite_migrator/migrations/util/migrate_yaml_config_1.py b/invokeai/app/services/shared/sqlite_migrator/migrations/util/migrate_yaml_config_1.py
index 2da998a532..fed15a1db1 100644
--- a/invokeai/app/services/shared/sqlite_migrator/migrations/util/migrate_yaml_config_1.py
+++ b/invokeai/app/services/shared/sqlite_migrator/migrations/util/migrate_yaml_config_1.py
@@ -3,7 +3,6 @@
 
 import json
 import sqlite3
-from hashlib import sha1
 from logging import Logger
 from pathlib import Path
 from typing import Optional
@@ -78,14 +77,22 @@ class MigrateModelYamlToDb1:
                 self.logger.warning(f"The model at {stanza.path} is not a valid file or directory. Skipping migration.")
                 continue
 
-            assert isinstance(model_key, str)
-            new_key = sha1(model_key.encode("utf-8")).hexdigest()
-
             stanza["base"] = BaseModelType(base_type)
             stanza["type"] = ModelType(model_type)
             stanza["name"] = model_name
             stanza["original_hash"] = hash
             stanza["current_hash"] = hash
+            new_key = hash  # deterministic key assignment
+
+            # special case for ip adapters, which need the new `image_encoder_model_id` field
+            if stanza["type"] == ModelType.IPAdapter:
+                try:
+                    stanza["image_encoder_model_id"] = self._get_image_encoder_model_id(
+                        self.config.models_path / stanza.path
+                    )
+                except OSError:
+                    self.logger.warning(f"Could not determine image encoder for {stanza.path}. Skipping.")
+                    continue
 
             new_config: AnyModelConfig = ModelsValidator.validate_python(stanza)  # type: ignore # see https://github.com/pydantic/pydantic/discussions/7094
 
@@ -95,7 +102,7 @@ class MigrateModelYamlToDb1:
                     self.logger.info(f"Updating model {model_name} with information from models.yaml using key {key}")
                     self._update_model(key, new_config)
                 else:
-                    self.logger.info(f"Adding model {model_name} with key {model_key}")
+                    self.logger.info(f"Adding model {model_name} with key {new_key}")
                     self._add_model(new_key, new_config)
             except DuplicateModelException:
                 self.logger.warning(f"Model {model_name} is already in the database")
@@ -149,3 +156,8 @@ class MigrateModelYamlToDb1:
             )
         except sqlite3.IntegrityError as exc:
             raise DuplicateModelException(f"{record.name}: model is already in database") from exc
+
+    def _get_image_encoder_model_id(self, model_path: Path) -> str:
+        with open(model_path / "image_encoder.txt") as f:
+            encoder = f.read()
+        return encoder.strip()
diff --git a/invokeai/backend/model_manager/hash.py b/invokeai/backend/model_manager/hash.py
index fb563a8cda..c4f4165ebf 100644
--- a/invokeai/backend/model_manager/hash.py
+++ b/invokeai/backend/model_manager/hash.py
@@ -28,14 +28,28 @@ class FastModelHash(object):
         """
         model_location = Path(model_location)
         if model_location.is_file():
-            return cls._hash_file(model_location)
+            return cls._hash_file_sha1(model_location)
         elif model_location.is_dir():
             return cls._hash_dir(model_location)
         else:
             raise OSError(f"Not a valid file or directory: {model_location}")
 
     @classmethod
-    def _hash_file(cls, model_location: Union[str, Path]) -> str:
+    def _hash_file_sha1(cls, model_location: Union[str, Path]) -> str:
+        """
+        Compute full sha1 hash over a single file and return its hexdigest.
+
+        :param model_location: Path to the model file
+        """
+        BLOCK_SIZE = 65536
+        file_hash = hashlib.sha1()
+        with open(model_location, "rb") as f:
+            data = f.read(BLOCK_SIZE)
+            file_hash.update(data)
+        return file_hash.hexdigest()
+
+    @classmethod
+    def _hash_file_fast(cls, model_location: Union[str, Path]) -> str:
         """
         Fasthash a single file and return its hexdigest.
 
@@ -56,7 +70,7 @@ class FastModelHash(object):
                 if not file.endswith((".ckpt", ".safetensors", ".bin", ".pt", ".pth")):
                     continue
                 path = (Path(root) / file).as_posix()
-                fast_hash = cls._hash_file(path)
+                fast_hash = cls._hash_file_fast(path)
                 components.update({path: fast_hash})
 
         # hash all the model hashes together, using alphabetic file order