{Ciphertext,Plaintext}Matrix deserialization

Sources/HomomorphicEncryption/SerializedPlaintext.swift

@@ -49,7 +49,7 @@ extension Plaintext where Format == Eval {
     ///   - serialized: Serialized plaintext.
     ///   - context: Context to associate with the plaintext.
     ///   - moduliCount: Optional number of moduli to associate with the plaintext. If not set, the plaintext will have
-    /// the top-level ciphertext context with all themoduli.
+    /// the top-level ciphertext context with all the moduli.
     /// - Throws: Error upon failure to deserialize.
     public init(deserialize serialized: SerializedPlaintext, context: Context<Scheme>, moduliCount: Int? = nil) throws {
         self.context = context

Sources/PrivateNearestNeighborsSearch/SerializedCiphertextMatrix.swift

@@ -44,6 +44,25 @@ public struct SerializedCiphertextMatrix<Scalar: ScalarType>: Equatable, Sendabl
 }
 
 extension CiphertextMatrix {
+    /// Deserializes a serialized ciphertext matrix.
+    /// - Parameters:
+    ///   - serialized: Serialized ciphertext matrix.
+    ///   - context: Context to associate with the ciphertext matrix.
+    ///   - moduliCount: Number of moduli in each serialized ciphertext. If not set, deserialization will use the
+    /// top-level ciphertext with all the moduli.
+    /// - Throws: Error upon failure to deserialize the ciphertext matrix.
+    @inlinable
+    public init(
+        deserialize serialized: SerializedCiphertextMatrix<Scheme.Scalar>,
+        context: Context<Scheme>,
+        moduliCount: Int? = nil) throws
+    {
+        let ciphertexts: [Ciphertext<Scheme, Format>] = try serialized.ciphertexts.map { serializedCiphertext in
+            try Ciphertext(deserialize: serializedCiphertext, context: context, moduliCount: moduliCount)
+        }
+        try self.init(dimensions: serialized.dimensions, packing: serialized.packing, ciphertexts: ciphertexts)
+    }
+
     /// Serializes the ciphertext matrix.
     /// - Parameter forDecryption: If true, serialization may use a more concise format, yielding ciphertexts which,
     /// once deserialized, are only compatible with decryption, and not any other HE operations.

Sources/PrivateNearestNeighborsSearch/SerializedPlaintextMatrix.swift

@@ -53,3 +53,37 @@ extension PlaintextMatrix {
             plaintexts: plaintexts.map { plaintext in plaintext.serialize() })
     }
 }
+
+extension PlaintextMatrix where Format == Coeff {
+    /// Deserializes a plaintext matrix.
+    /// - Parameters:
+    ///   - serialized: Serialized plaintext matrix.
+    ///   - context: Context to associate with the plaintext matrix.
+    /// - Throws: Error upon failure to deserialize.
+    init(deserialize serialized: SerializedPlaintextMatrix, context: Context<Scheme>) throws {
+        let plaintexts = try serialized.plaintexts.map { serializedPlaintext in
+            try Plaintext(deserialize: serializedPlaintext, context: context)
+        }
+        try self.init(dimensions: serialized.dimensions, packing: serialized.packing, plaintexts: plaintexts)
+    }
+}
+
+extension PlaintextMatrix where Format == Eval {
+    /// Deserializes a plaintext matrix.
+    /// - Parameters:
+    ///   - serialized: Serialized plaintext matrix.
+    ///   - context: Context to associate with the plaintext matrix.
+    ///   - moduliCount: Optional number of moduli to associate with each plaintext. If not set, each plaintext will
+    /// have the top-level ciphertext context with all the moduli.
+    /// - Throws: Error upon failure to deserialize.
+    init(
+        deserialize serialized: SerializedPlaintextMatrix,
+        context: Context<Scheme>,
+        moduliCount: Int? = nil) throws
+    {
+        let plaintexts = try serialized.plaintexts.map { serializedPlaintext in
+            try Plaintext(deserialize: serializedPlaintext, context: context, moduliCount: moduliCount)
+        }
+        try self.init(dimensions: serialized.dimensions, packing: serialized.packing, plaintexts: plaintexts)
+    }
+}

Tests/PrivateNearestNeighborsSearchProtobufTests/ConversionTests.swift

@@ -108,6 +108,19 @@ class ConversionTests: XCTestCase {
                 values: scalars.flatMap { $0 })
             let serialized = try plaintextMatrix.serialize()
             XCTAssertEqual(try serialized.proto().native(), serialized)
+            let deserialized = try PlaintextMatrix(deserialize: serialized, context: context)
+            XCTAssertEqual(deserialized, plaintextMatrix)
+
+            for moduliCount in 1..<encryptionParams.coefficientModuli.count {
+                let evalPlaintextMatrix = try plaintextMatrix.convertToEvalFormat(moduliCount: moduliCount)
+                let serialized = try evalPlaintextMatrix.serialize()
+                XCTAssertEqual(try serialized.proto().native(), serialized)
+                let deserialized = try PlaintextMatrix(
+                    deserialize: serialized,
+                    context: context,
+                    moduliCount: moduliCount)
+                XCTAssertEqual(deserialized, evalPlaintextMatrix)
+            }
         }
 
         try runTest(Bfv<UInt32>.self)
@@ -135,10 +148,25 @@ class ConversionTests: XCTestCase {
             XCTAssertEqual(try serializedProto.native(), serialized)
             let serializedSize = try serializedProto.serializedData().count
 
-            // TODO: test deserialization
             let serializedForDecryption = try ciphertextMatrix.serialize(forDecryption: true)
             let serializedForDecryptionSize = try serializedForDecryption.proto().serializedData().count
             XCTAssertLessThanOrEqual(serializedForDecryptionSize, serializedSize)
+            let deserialized = try CiphertextMatrix<Scheme, Scheme.CanonicalCiphertextFormat>(
+                deserialize: serializedForDecryption,
+                context: context)
+            let decrypted = try deserialized.decrypt(using: secretKey)
+            XCTAssertEqual(decrypted, plaintextMatrix)
+
+            // Check Evaluation format
+            do {
+                let evalCiphertextMatrix = try ciphertextMatrix.convertToEvalFormat()
+                let serialized = try evalCiphertextMatrix.serialize()
+                XCTAssertEqual(try serialized.proto().native(), serialized)
+                let deserialized = try CiphertextMatrix<Scheme, Eval>(
+                    deserialize: serialized,
+                    context: context)
+                XCTAssertEqual(deserialized, evalCiphertextMatrix)
+            }
         }
 
         try runTest(Bfv<UInt32>.self)