diff --git a/Project.toml b/Project.toml
index 0e4d6eb..56bc5ff 100644
--- a/Project.toml
+++ b/Project.toml
@@ -7,5 +7,5 @@ version = "0.1.0"
 OpenFHE = "77ce9b8e-ecf5-45d1-bd8a-d31f384f2f95"
 
 [compat]
-OpenFHE = "0.1"
+OpenFHE = "0.1.5"
 julia = "1.8"
diff --git a/src/arithmetic.jl b/src/arithmetic.jl
index 0662f4c..10d757e 100644
--- a/src/arithmetic.jl
+++ b/src/arithmetic.jl
@@ -1,15 +1,22 @@
+# Add
 Base.:+(sv1::SecureVector, sv2::SecureVector) = add(sv1, sv2)
 Base.:+(sv::SecureVector, pv::PlainVector) = add(sv, pv)
 Base.:+(pv::PlainVector, sv::SecureVector) = add(sv, pv)
 
+# Subtract
 Base.:-(sv1::SecureVector, sv2::SecureVector) = subtract(sv1, sv2)
 Base.:-(sv::SecureVector, pv::PlainVector) = subtract(sv, pv)
 Base.:-(pv::PlainVector, sv::SecureVector) = subtract(pv, sv)
 
+# Negate
+Base.:-(sv::SecureVector) = negate(sv)
+
+# Multiply
 Base.:*(sv1::SecureVector, sv2::SecureVector) = multiply(sv1, sv2)
 Base.:*(sv::SecureVector, pv::PlainVector) = multiply(sv, pv)
 Base.:*(pv::PlainVector, sv::SecureVector) = multiply(sv, pv)
 Base.:*(sv::SecureVector, scalar::Real) = multiply(sv, scalar)
 Base.:*(scalar::Real, sv::SecureVector) = multiply(sv, scalar)
 
+# Circular shift
 Base.circshift(sv::SecureVector, shift::Integer) = rotate(sv, shift)
diff --git a/src/openfhe.jl b/src/openfhe.jl
index 3842802..a328033 100644
--- a/src/openfhe.jl
+++ b/src/openfhe.jl
@@ -101,6 +101,14 @@ function add(sv1::SecureVector{<:OpenFHEBackend}, sv2::SecureVector{<:OpenFHEBac
     secure_vector
 end
 
+function add(sv::SecureVector{<:OpenFHEBackend}, pv::PlainVector{<:OpenFHEBackend})
+    cc = get_crypto_context(sv)
+    ciphertext = OpenFHE.EvalAdd(cc, sv.ciphertext, pv.plaintext)
+    secure_vector = SecureVector(ciphertext, sv.context)
+
+    secure_vector
+end
+
 function subtract(sv1::SecureVector{<:OpenFHEBackend}, sv2::SecureVector{<:OpenFHEBackend})
     cc = get_crypto_context(sv1)
     ciphertext = OpenFHE.EvalSub(cc, sv1.ciphertext, sv2.ciphertext)
@@ -109,6 +117,30 @@ function subtract(sv1::SecureVector{<:OpenFHEBackend}, sv2::SecureVector{<:OpenF
     secure_vector
 end
 
+function subtract(sv::SecureVector{<:OpenFHEBackend}, pv::PlainVector{<:OpenFHEBackend})
+    cc = get_crypto_context(sv)
+    ciphertext = OpenFHE.EvalSub(cc, sv.ciphertext, pv.plaintext)
+    secure_vector = SecureVector(ciphertext, sv.context)
+
+    secure_vector
+end
+
+function subtract(pv::PlainVector{<:OpenFHEBackend}, sv::SecureVector{<:OpenFHEBackend})
+    cc = get_crypto_context(sv)
+    ciphertext = OpenFHE.EvalSub(cc, pv.plaintext, sv.ciphertext)
+    secure_vector = SecureVector(ciphertext, sv.context)
+
+    secure_vector
+end
+
+function negate(sv::SecureVector{<:OpenFHEBackend})
+    cc = get_crypto_context(sv)
+    ciphertext = OpenFHE.EvalNegate(cc, sv.ciphertext)
+    secure_vector = SecureVector(ciphertext, sv.context)
+
+    secure_vector
+end
+
 function multiply(sv1::SecureVector{<:OpenFHEBackend}, sv2::SecureVector{<:OpenFHEBackend})
     cc = get_crypto_context(sv1)
     ciphertext = OpenFHE.EvalMult(cc, sv1.ciphertext, sv2.ciphertext)
diff --git a/src/unencrypted.jl b/src/unencrypted.jl
index ae6cff9..9b39d78 100644
--- a/src/unencrypted.jl
+++ b/src/unencrypted.jl
@@ -39,10 +39,26 @@ function add(sv1::SecureVector{<:Unencrypted}, sv2::SecureVector{<:Unencrypted})
     SecureVector(sv1.ciphertext .+ sv2.ciphertext, sv1.context)
 end
 
+function add(sv::SecureVector{<:Unencrypted}, pv::PlainVector{<:Unencrypted})
+    SecureVector(sv.ciphertext .+ pv.plaintext, sv.context)
+end
+
 function subtract(sv1::SecureVector{<:Unencrypted}, sv2::SecureVector{<:Unencrypted})
     SecureVector(sv1.ciphertext .- sv2.ciphertext, sv1.context)
 end
 
+function subtract(sv::SecureVector{<:Unencrypted}, pv::PlainVector{<:Unencrypted})
+    SecureVector(sv.ciphertext .- pv.plaintext, sv.context)
+end
+
+function subtract(pv::PlainVector{<:Unencrypted}, sv::SecureVector{<:Unencrypted})
+    SecureVector(pv.plaintext .- sv.ciphertext, sv.context)
+end
+
+function negate(sv::SecureVector{<:Unencrypted})
+    SecureVector(-sv.ciphertext, sv.context)
+end
+
 function multiply(sv1::SecureVector{<:Unencrypted}, sv2::SecureVector{<:Unencrypted})
     SecureVector(sv1.ciphertext .* sv2.ciphertext, sv1.context)
 end
diff --git a/test/runtests.jl b/test/runtests.jl
index c8217d2..7c0c6ef 100644
--- a/test/runtests.jl
+++ b/test/runtests.jl
@@ -2,5 +2,6 @@ using Test
 
 @time @testset verbose=true showtiming=true "SecureArithmetic.jl tests" begin
     include("test_examples.jl")
+    include("test_unit.jl")
 end
 
diff --git a/test/test_unit.jl b/test/test_unit.jl
new file mode 100644
index 0000000..d843cf0
--- /dev/null
+++ b/test/test_unit.jl
@@ -0,0 +1,92 @@
+module TestUnit
+
+using Test
+using SecureArithmetic
+using OpenFHE
+
+@testset verbose=true showtiming=true "test_unit.jl" begin
+
+# Set up OpenFHE backend
+multiplicative_depth = 1
+scaling_modulus = 50
+batch_size = 8
+
+parameters = CCParams{CryptoContextCKKSRNS}()
+SetMultiplicativeDepth(parameters, multiplicative_depth)
+SetScalingModSize(parameters, scaling_modulus)
+SetBatchSize(parameters, batch_size)
+
+cc = GenCryptoContext(parameters)
+Enable(cc, PKE)
+Enable(cc, KEYSWITCH)
+Enable(cc, LEVELEDSHE)
+context_openfhe = SecureContext(OpenFHEBackend(cc))
+
+# Set up unencrypted backend
+context_unencrypted = SecureContext(Unencrypted())
+
+for backend in ((; name = "OpenFHE", BackendT = OpenFHEBackend, context = context_openfhe),
+                (; name = "Unencrypted", BackendT = Unencrypted, context = context_unencrypted))
+    (; name, BackendT, context) = backend
+
+    @testset verbose=true showtiming=true "$name" begin
+        @testset verbose=true showtiming=true "generate_keys" begin
+            @test_nowarn generate_keys(context)
+        end
+        public_key, private_key = generate_keys(context)
+
+        @testset verbose=true showtiming=true "init_multiplication!" begin
+            @test_nowarn init_multiplication!(context, private_key)
+        end
+
+        @testset verbose=true showtiming=true "init_rotation!" begin
+            @test_nowarn init_rotation!(context, private_key, [1, -2])
+        end
+
+        x1 = [0.25, 0.5, 0.75, 1.0, 2.0, 3.0, 4.0, 5.0]
+        x2 = [5.0, 4.0, 3.0, 2.0, 1.0, 0.75, 0.5, 0.25]
+
+        @testset verbose=true showtiming=true "PlainVector" begin
+            @test PlainVector(x1, context) isa PlainVector
+        end
+
+        pv1 = PlainVector(x1, context)
+        pv2 = PlainVector(x2, context)
+
+        @testset verbose=true showtiming=true "encrypt" begin
+            @test encrypt(pv1, public_key) isa SecureVector
+        end
+
+        sv1 = encrypt(pv1, public_key)
+        sv2 = encrypt(pv2, public_key)
+
+        @testset verbose=true showtiming=true "add" begin
+            @test sv1 + sv2 isa SecureVector
+            @test sv1 + pv1 isa SecureVector
+            @test pv1 + sv1 isa SecureVector
+        end
+
+        @testset verbose=true showtiming=true "subtract" begin
+            @test sv1 - sv2 isa SecureVector
+            @test sv1 - pv1 isa SecureVector
+            @test pv1 - sv1 isa SecureVector
+        end
+
+        @testset verbose=true showtiming=true "multiply" begin
+            @test sv1 * sv2 isa SecureVector
+            @test sv1 * pv1 isa SecureVector
+            @test pv1 * sv1 isa SecureVector
+            @test sv1 * 3 isa SecureVector
+            @test 4 * sv1 isa SecureVector
+        end
+
+        @testset verbose=true showtiming=true "negate" begin
+            @test -sv2 isa SecureVector
+        end
+    end
+end
+
+end # @testset "test_unit.jl"
+
+end # module
+