prompt: We are currently solving the following issue within our repository. Here is the issue text:
  --- BEGIN ISSUE ---
  FV cipher-text data change during decryption.
  ## Description
  During the decryption process, the ciphertext was soft copied and it changed the ciphertext value during decryption. So we lose the value of ciphertext.
  ## How to Reproduce
  1. Create a ciphertext
  2. Decrypt that ciphertext
  3. Retry to decrypt the same ciphertext (wrong result)
  
  
  --- END ISSUE ---
  
  Below are some code segments, each from a relevant file. One or more of these files may contain bugs.
  --- BEGIN FILES ---
  Path: `syft/frameworks/torch/he/fv/decryptor.py`
  Content:
  ```
  1 from numpy.polynomial import polynomial as poly
  2 
  3 
  4 from syft.frameworks.torch.he.fv.plaintext import PlainText
  5 from syft.frameworks.torch.he.fv.util.operations import get_significant_count
  6 from syft.frameworks.torch.he.fv.util.operations import poly_add_mod
  7 from syft.frameworks.torch.he.fv.util.operations import poly_mul_mod
  8 
  9 
  10 class Decryptor:
  11     """Decrypts Ciphertext objects into Plaintext objects.
  12 
  13     Args:
  14         context (Context): Context for extracting encryption parameters.
  15         secret_key: A secret key from same pair of keys(secretkey or publickey) used in encryptor.
  16     """
  17 
  18     def __init__(self, context, secret_key):
  19         self._context = context
  20         self._coeff_modulus = context.param.coeff_modulus
  21         self._coeff_count = context.param.poly_modulus
  22         self._secret_key = secret_key.data
  23 
  24     def decrypt(self, encrypted):
  25         """Decrypts the encrypted ciphertext objects.
  26 
  27         Args:
  28             encrypted: A ciphertext object which has to be decrypted.
  29 
  30         Returns:
  31             A PlainText object containing the decrypted result.
  32         """
  33 
  34         # Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q
  35         temp_product_modq = self._mul_ct_sk(encrypted.data)
  36 
  37         # Divide scaling variant using BEHZ FullRNS techniques
  38         result = self._context.rns_tool.decrypt_scale_and_round(temp_product_modq)
  39 
  40         # removing leading zeroes in plaintext representation.
  41         plain_coeff_count = get_significant_count(result)
  42         return PlainText(result[:plain_coeff_count])
  43 
  44     def _mul_ct_sk(self, encrypted):
  45         """Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q
  46 
  47         where [c0, c1, ...] represents ciphertext element and sk^n represents
  48         secret key raised to the power n.
  49 
  50         Args:
  51             encrypted: A ciphertext object of encrypted data.
  52 
  53         Returns:
  54             A 2-dim list containing result of [c0 + c1 * sk + c2 * sk^2 ...]_q.
  55         """
  56         phase = encrypted[0]
  57 
  58         secret_key_array = self._get_sufficient_sk_power(len(encrypted))
  59 
  60         for j in range(1, len(encrypted)):
  61             for i in range(len(self._coeff_modulus)):
  62                 phase[i] = poly_add_mod(
  63                     poly_mul_mod(
  64                         encrypted[j][i], secret_key_array[j - 1][i], self._coeff_modulus[i]
  65                     ),
  66                     phase[i],
  67                     self._coeff_modulus[i],
  68                 )
  69 
  70         return phase
  71 
  72     def _get_sufficient_sk_power(self, max_power):
  73         """Generate an list of secret key polynomial raised to 1...max_power.
  74 
  75         Args:
  76             max_power: heighest power up to which we want to raise secretkey.
  77 
  78         Returns:
  79             A 2-dim list having secretkey powers.
  80         """
  81         sk_power = [[] for _ in range(max_power)]
  82 
  83         sk_power[0] = self._secret_key
  84 
  85         for i in range(2, max_power + 1):
  86             for j in range(len(self._coeff_modulus)):
  87                 sk_power[i - 1].append(poly.polypow(self._secret_key[j], i).astype(int).tolist())
  88         return sk_power
  89
  ```
  --- END FILES ---
  
  Please first localize the bug based on the issue statement, and then generate a patch according to the `git diff` format fenced by three backticks.
  
  Here is an example:
  
  ```diff
  diff --git a/examples/server_async.py b/examples/server_async.py
  --- a/examples/server_async.py
  +++ b/examples/server_async.py
  @@ -313,4 +313,4 @@
   
   
   if __name__ == "__main__":
  -    asyncio.run(run_async_server("."), debug=True)
  +    asyncio.run(run_async_server(), debug=True)
  diff --git a/examples/server_sync.py b/examples/server_sync.py
  --- a/examples/server_sync.py
  +++ b/examples/server_sync.py
  @@ -313,5 +313,5 @@
   
   
   if __name__ == "__main__":
  -    server = run_sync_server(".")
  +    server = run_sync_server()
       server.shutdown()
  
  ```
  
golden_diff: diff --git a/syft/frameworks/torch/he/fv/decryptor.py b/syft/frameworks/torch/he/fv/decryptor.py
  --- a/syft/frameworks/torch/he/fv/decryptor.py
  +++ b/syft/frameworks/torch/he/fv/decryptor.py
  @@ -1,3 +1,4 @@
  +import copy
   from numpy.polynomial import polynomial as poly
   
   
  @@ -32,7 +33,7 @@
           """
   
           # Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q
  -        temp_product_modq = self._mul_ct_sk(encrypted.data)
  +        temp_product_modq = self._mul_ct_sk(copy.deepcopy(encrypted.data))
   
           # Divide scaling variant using BEHZ FullRNS techniques
           result = self._context.rns_tool.decrypt_scale_and_round(temp_product_modq)
  
verification_info: {"golden_diff": "diff --git a/syft/frameworks/torch/he/fv/decryptor.py b/syft/frameworks/torch/he/fv/decryptor.py\n--- a/syft/frameworks/torch/he/fv/decryptor.py\n+++ b/syft/frameworks/torch/he/fv/decryptor.py\n@@ -1,3 +1,4 @@\n+import copy\n from numpy.polynomial import polynomial as poly\n \n \n@@ -32,7 +33,7 @@\n         \"\"\"\n \n         # Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q\n-        temp_product_modq = self._mul_ct_sk(encrypted.data)\n+        temp_product_modq = self._mul_ct_sk(copy.deepcopy(encrypted.data))\n \n         # Divide scaling variant using BEHZ FullRNS techniques\n         result = self._context.rns_tool.decrypt_scale_and_round(temp_product_modq)\n", "issue": "FV cipher-text data change during decryption.\n## Description\r\nDuring the decryption process, the ciphertext was soft copied and it changed the ciphertext value during decryption. So we lose the value of ciphertext.\r\n## How to Reproduce\r\n1. Create a ciphertext\r\n2. Decrypt that ciphertext\r\n3. Retry to decrypt the same ciphertext (wrong result)\r\n\n", "before_files": [{"content": "from numpy.polynomial import polynomial as poly\n\n\nfrom syft.frameworks.torch.he.fv.plaintext import PlainText\nfrom syft.frameworks.torch.he.fv.util.operations import get_significant_count\nfrom syft.frameworks.torch.he.fv.util.operations import poly_add_mod\nfrom syft.frameworks.torch.he.fv.util.operations import poly_mul_mod\n\n\nclass Decryptor:\n    \"\"\"Decrypts Ciphertext objects into Plaintext objects.\n\n    Args:\n        context (Context): Context for extracting encryption parameters.\n        secret_key: A secret key from same pair of keys(secretkey or publickey) used in encryptor.\n    \"\"\"\n\n    def __init__(self, context, secret_key):\n        self._context = context\n        self._coeff_modulus = context.param.coeff_modulus\n        self._coeff_count = context.param.poly_modulus\n        self._secret_key = secret_key.data\n\n    def decrypt(self, encrypted):\n        \"\"\"Decrypts the encrypted ciphertext objects.\n\n        Args:\n            encrypted: A ciphertext object which has to be decrypted.\n\n        Returns:\n            A PlainText object containing the decrypted result.\n        \"\"\"\n\n        # Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q\n        temp_product_modq = self._mul_ct_sk(encrypted.data)\n\n        # Divide scaling variant using BEHZ FullRNS techniques\n        result = self._context.rns_tool.decrypt_scale_and_round(temp_product_modq)\n\n        # removing leading zeroes in plaintext representation.\n        plain_coeff_count = get_significant_count(result)\n        return PlainText(result[:plain_coeff_count])\n\n    def _mul_ct_sk(self, encrypted):\n        \"\"\"Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q\n\n        where [c0, c1, ...] represents ciphertext element and sk^n represents\n        secret key raised to the power n.\n\n        Args:\n            encrypted: A ciphertext object of encrypted data.\n\n        Returns:\n            A 2-dim list containing result of [c0 + c1 * sk + c2 * sk^2 ...]_q.\n        \"\"\"\n        phase = encrypted[0]\n\n        secret_key_array = self._get_sufficient_sk_power(len(encrypted))\n\n        for j in range(1, len(encrypted)):\n            for i in range(len(self._coeff_modulus)):\n                phase[i] = poly_add_mod(\n                    poly_mul_mod(\n                        encrypted[j][i], secret_key_array[j - 1][i], self._coeff_modulus[i]\n                    ),\n                    phase[i],\n                    self._coeff_modulus[i],\n                )\n\n        return phase\n\n    def _get_sufficient_sk_power(self, max_power):\n        \"\"\"Generate an list of secret key polynomial raised to 1...max_power.\n\n        Args:\n            max_power: heighest power up to which we want to raise secretkey.\n\n        Returns:\n            A 2-dim list having secretkey powers.\n        \"\"\"\n        sk_power = [[] for _ in range(max_power)]\n\n        sk_power[0] = self._secret_key\n\n        for i in range(2, max_power + 1):\n            for j in range(len(self._coeff_modulus)):\n                sk_power[i - 1].append(poly.polypow(self._secret_key[j], i).astype(int).tolist())\n        return sk_power\n", "path": "syft/frameworks/torch/he/fv/decryptor.py"}], "after_files": [{"content": "import copy\nfrom numpy.polynomial import polynomial as poly\n\n\nfrom syft.frameworks.torch.he.fv.plaintext import PlainText\nfrom syft.frameworks.torch.he.fv.util.operations import get_significant_count\nfrom syft.frameworks.torch.he.fv.util.operations import poly_add_mod\nfrom syft.frameworks.torch.he.fv.util.operations import poly_mul_mod\n\n\nclass Decryptor:\n    \"\"\"Decrypts Ciphertext objects into Plaintext objects.\n\n    Args:\n        context (Context): Context for extracting encryption parameters.\n        secret_key: A secret key from same pair of keys(secretkey or publickey) used in encryptor.\n    \"\"\"\n\n    def __init__(self, context, secret_key):\n        self._context = context\n        self._coeff_modulus = context.param.coeff_modulus\n        self._coeff_count = context.param.poly_modulus\n        self._secret_key = secret_key.data\n\n    def decrypt(self, encrypted):\n        \"\"\"Decrypts the encrypted ciphertext objects.\n\n        Args:\n            encrypted: A ciphertext object which has to be decrypted.\n\n        Returns:\n            A PlainText object containing the decrypted result.\n        \"\"\"\n\n        # Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q\n        temp_product_modq = self._mul_ct_sk(copy.deepcopy(encrypted.data))\n\n        # Divide scaling variant using BEHZ FullRNS techniques\n        result = self._context.rns_tool.decrypt_scale_and_round(temp_product_modq)\n\n        # removing leading zeroes in plaintext representation.\n        plain_coeff_count = get_significant_count(result)\n        return PlainText(result[:plain_coeff_count])\n\n    def _mul_ct_sk(self, encrypted):\n        \"\"\"Calculate [c0 + c1 * sk + c2 * sk^2 ...]_q\n\n        where [c0, c1, ...] represents ciphertext element and sk^n represents\n        secret key raised to the power n.\n\n        Args:\n            encrypted: A ciphertext object of encrypted data.\n\n        Returns:\n            A 2-dim list containing result of [c0 + c1 * sk + c2 * sk^2 ...]_q.\n        \"\"\"\n        phase = encrypted[0]\n\n        secret_key_array = self._get_sufficient_sk_power(len(encrypted))\n\n        for j in range(1, len(encrypted)):\n            for i in range(len(self._coeff_modulus)):\n                phase[i] = poly_add_mod(\n                    poly_mul_mod(\n                        encrypted[j][i], secret_key_array[j - 1][i], self._coeff_modulus[i]\n                    ),\n                    phase[i],\n                    self._coeff_modulus[i],\n                )\n\n        return phase\n\n    def _get_sufficient_sk_power(self, max_power):\n        \"\"\"Generate an list of secret key polynomial raised to 1...max_power.\n\n        Args:\n            max_power: heighest power up to which we want to raise secretkey.\n\n        Returns:\n            A 2-dim list having secretkey powers.\n        \"\"\"\n        sk_power = [[] for _ in range(max_power)]\n\n        sk_power[0] = self._secret_key\n\n        for i in range(2, max_power + 1):\n            for j in range(len(self._coeff_modulus)):\n                sk_power[i - 1].append(poly.polypow(self._secret_key[j], i).astype(int).tolist())\n        return sk_power\n", "path": "syft/frameworks/torch/he/fv/decryptor.py"}]}