class Patient
  include Mongoid::Document
 
  encrypt_metadata: {
	key_id: "uuid of your Data Encryption Key"
  }
 
  field :medical_records, type: Array, encrypt: {
	deterministic: false
  }
 
  field :blood_type, type: String, encrypt: {
	deterministic: false
  }
 
  field :ssn, type: Integer, encrypt: {
	deterministic: true
  }
 
  embeds_one :insurance
end

class Insurance
  include Mongoid::Document
 
  field :policy_number, type: Integer, encrypt: {
	deterministic: true
  }
 
  embedded_in :patient
end

{
  "medicalRecords.patients": {
    "bsonType": "object",
    "encryptMetadata": {
     "keyId": [UUID("<_id of your Data Encryption Key>" )]
   },
    "properties": {
      "insurance": {
        "bsonType": "object",
        "properties": {
          "policyNumber": {
            "encrypt": {
              "bsonType": "int",
              "algorithm": "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic"
            }
          }
        }
      },
      "medical_records": {
        "encrypt": {
          "bsonType": "array",
          "algorithm": "AEAD_AES_256_CBC_HMAC_SHA_512-Random"
        }
      },
      "blood_type": {
        "encrypt": {
          "bsonType": "string",
          "algorithm": "AEAD_AES_256_CBC_HMAC_SHA_512-Random"
        }
      },
      "ssn": {
        "encrypt": {
          "bsonType": "int",
          "algorithm": "AEAD_AES_256_CBC_HMAC_SHA_512-Deterministic"
        }
      }
    }
  }
}