diff --git a/src/signature.ts b/src/signature.ts
index e2abae2..50a73b5 100644
--- a/src/signature.ts
+++ b/src/signature.ts
@@ -7,8 +7,13 @@ export async function gen_privkey() : Promise<Uint8Array> {
     log.trace("generate keypair")
     return ed.utils.randomPrivateKey()
 }
+export async function gen_keypair() : Promise<[Uint8Array, Uint8Array]> {
+    const privkey = await gen_privkey()
+    const pubkey = await get_pubkey(privkey)
+    return [privkey, pubkey]
+}
 export async function get_pubkey(privkey: Uint8Array) : Promise<Uint8Array> {
-    log.trace("derive pubky")
+    log.trace("derive pubkey")
     return ed.getPublicKeyAsync(privkey)
 }
 export async function sign(message: Uint8Array, privkey: Uint8Array) : Promise<Uint8Array> {
diff --git a/test/signature.test.ts b/test/signature.test.ts
new file mode 100644
index 0000000..47209a0
--- /dev/null
+++ b/test/signature.test.ts
@@ -0,0 +1,55 @@
+import {test, expect} from 'bun:test'
+
+import {signature} from '../index'
+import {gen_keypair} from "../src/signature";
+
+test('base case', async () => {
+    const keypair = await gen_keypair()
+    const data = new TextEncoder().encode("Message 123 !")
+
+    const sig = await signature.sign(data, keypair[0])
+    const verification = await signature.verify(data, keypair[1], sig)
+
+    expect(verification).toBe(true)
+})
+
+test('inverted keys', async () => {
+    const keypair = await signature.gen_keypair()
+    const data = new TextEncoder().encode("Message 123 !")
+
+    expect(async () => await signature.sign(keypair[1], data)).toThrow()
+})
+
+test('tampered message', async () => {
+    const keypair = await signature.gen_keypair()
+    const data1 = new TextEncoder().encode("Message 123 !")
+    const data2 = new TextEncoder().encode("Message 321 !")
+    expect(data1).not.toEqual(data2)
+
+    const sig = await signature.sign(data1, keypair[0])
+    const verification = await signature.verify(data2, keypair[1], sig)
+
+    expect(verification).toBe(false)
+})
+
+test('different keypair', async () => {
+    const keypair = await signature.gen_keypair()
+    const keypair2 = await signature.gen_keypair()
+    const data = new TextEncoder().encode("Message 123 !")
+
+    const sig = await signature.sign(data, keypair[0])
+    const verification = await signature.verify(data, keypair2[1], sig)
+
+    expect(verification).toBe(false)
+})
+
+test('tampered signature', async () => {
+    const keypair = await signature.gen_keypair()
+    const data = new TextEncoder().encode("Message 123 !")
+
+    const sig = await signature.sign(data, keypair[0])
+    sig[0] ^= 1
+    const verification = await signature.verify(data, keypair[1], sig)
+
+    expect(verification).toBe(false)
+})