diff --git a/CHANGELOG.md b/CHANGELOG.md
index 7285afae..7e3e53c7 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -24,6 +24,11 @@ and this project adheres to
   `SigningStargateClient`.
 - @cosmjs/amino: New package created that contains the shared amino signing
   functionality for @cosmjs/launchpad and @cosmjs/stargate.
+- @cosmjs/amino: Split public key interfaces into `Pubkey`, `SinglePubkey` and
+  `Secp256k1Pubkey` where `Pubkey` is a generalization of the old `PubKey` that
+  supported nested pubkeys for multisig. `SinglePubkey` is the old `PubKey` in
+  which the `value` is a base64 encoded string. And `Secp256k1Pubkey` is a
+  single secp256k1 pubkey.
 
 ### Changed
 
diff --git a/packages/amino/src/encoding.spec.ts b/packages/amino/src/encoding.spec.ts
index 02c6900d..e3f60f56 100644
--- a/packages/amino/src/encoding.spec.ts
+++ b/packages/amino/src/encoding.spec.ts
@@ -7,9 +7,9 @@ import {
   encodeBech32Pubkey,
   encodeSecp256k1Pubkey,
 } from "./encoding";
-import { PubKey } from "./pubkeys";
+import { Pubkey } from "./pubkeys";
 
-describe("pubkey", () => {
+describe("encoding", () => {
   describe("encodeSecp256k1Pubkey", () => {
     it("encodes a compresed pubkey", () => {
       const pubkey = fromBase64("AtQaCqFnshaZQp6rIkvAPyzThvCvXSDO+9AzbxVErqJP");
@@ -85,7 +85,7 @@ describe("pubkey", () => {
 
   describe("encodeAminoPubkey", () => {
     it("works for secp256k1", () => {
-      const pubkey: PubKey = {
+      const pubkey: Pubkey = {
         type: "tendermint/PubKeySecp256k1",
         value: "A08EGB7ro1ORuFhjOnZcSgwYlpe0DSFjVNUIkNNQxwKQ",
       };
@@ -98,7 +98,7 @@ describe("pubkey", () => {
     it("works for ed25519", () => {
       // Decoded from http://localhost:26657/validators
       // Encoded from `corald tendermint show-validator`
-      const pubkey: PubKey = {
+      const pubkey: Pubkey = {
         type: "tendermint/PubKeyEd25519",
         value: "YZHlYxP5R6olj3Tj3f7VgkQE5VaOvv9G0jKATqdQsqI=",
       };
@@ -111,7 +111,7 @@ describe("pubkey", () => {
 
   describe("encodeBech32Pubkey", () => {
     it("works for secp256k1", () => {
-      const pubkey: PubKey = {
+      const pubkey: Pubkey = {
         type: "tendermint/PubKeySecp256k1",
         value: "A08EGB7ro1ORuFhjOnZcSgwYlpe0DSFjVNUIkNNQxwKQ",
       };
@@ -123,7 +123,7 @@ describe("pubkey", () => {
     it("works for ed25519", () => {
       // Decoded from http://localhost:26657/validators
       // Encoded from `corald tendermint show-validator`
-      const pubkey: PubKey = {
+      const pubkey: Pubkey = {
         type: "tendermint/PubKeyEd25519",
         value: "YZHlYxP5R6olj3Tj3f7VgkQE5VaOvv9G0jKATqdQsqI=",
       };
diff --git a/packages/amino/src/encoding.ts b/packages/amino/src/encoding.ts
index cc6297a0..58ba9202 100644
--- a/packages/amino/src/encoding.ts
+++ b/packages/amino/src/encoding.ts
@@ -1,9 +1,9 @@
 import { Bech32, fromBase64, fromHex, toBase64, toHex } from "@cosmjs/encoding";
 import { arrayContentEquals } from "@cosmjs/utils";
 
-import { PubKey, pubkeyType } from "./pubkeys";
+import { Pubkey, pubkeyType, Secp256k1Pubkey } from "./pubkeys";
 
-export function encodeSecp256k1Pubkey(pubkey: Uint8Array): PubKey {
+export function encodeSecp256k1Pubkey(pubkey: Uint8Array): Secp256k1Pubkey {
   if (pubkey.length !== 33 || (pubkey[0] !== 0x02 && pubkey[0] !== 0x03)) {
     throw new Error("Public key must be compressed secp256k1, i.e. 33 bytes starting with 0x02 or 0x03");
   }
@@ -24,7 +24,7 @@ const pubkeyAminoPrefixLength = pubkeyAminoPrefixSecp256k1.length;
 /**
  * Decodes a pubkey in the Amino binary format to a type/value object.
  */
-export function decodeAminoPubkey(data: Uint8Array): PubKey {
+export function decodeAminoPubkey(data: Uint8Array): Pubkey {
   const aminoPrefix = data.slice(0, pubkeyAminoPrefixLength);
   const rest = data.slice(pubkeyAminoPrefixLength);
   if (arrayContentEquals(aminoPrefix, pubkeyAminoPrefixSecp256k1)) {
@@ -62,7 +62,7 @@ export function decodeAminoPubkey(data: Uint8Array): PubKey {
  *
  * @param bechEncoded the bech32 encoded pubkey
  */
-export function decodeBech32Pubkey(bechEncoded: string): PubKey {
+export function decodeBech32Pubkey(bechEncoded: string): Pubkey {
   const { data } = Bech32.decode(bechEncoded);
   return decodeAminoPubkey(data);
 }
@@ -70,7 +70,7 @@ export function decodeBech32Pubkey(bechEncoded: string): PubKey {
 /**
  * Encodes a public key to binary Amino.
  */
-export function encodeAminoPubkey(pubkey: PubKey): Uint8Array {
+export function encodeAminoPubkey(pubkey: Pubkey): Uint8Array {
   let aminoPrefix: Uint8Array;
   switch (pubkey.type) {
     // Note: please don't add cases here without writing additional unit tests
@@ -92,6 +92,6 @@ export function encodeAminoPubkey(pubkey: PubKey): Uint8Array {
  * @param pubkey the public key to encode
  * @param prefix the bech32 prefix (human readable part)
  */
-export function encodeBech32Pubkey(pubkey: PubKey, prefix: string): string {
+export function encodeBech32Pubkey(pubkey: Pubkey, prefix: string): string {
   return Bech32.encode(prefix, encodeAminoPubkey(pubkey));
 }
diff --git a/packages/amino/src/index.ts b/packages/amino/src/index.ts
index 7f01fc17..5469771a 100644
--- a/packages/amino/src/index.ts
+++ b/packages/amino/src/index.ts
@@ -5,4 +5,4 @@ export {
   encodeBech32Pubkey,
   encodeSecp256k1Pubkey,
 } from "./encoding";
-export { PubKey, pubkeyType } from "./pubkeys";
+export { Pubkey, Secp256k1Pubkey, SinglePubkey, isSinglePubkey, pubkeyType } from "./pubkeys";
diff --git a/packages/amino/src/pubkeys.spec.ts b/packages/amino/src/pubkeys.spec.ts
new file mode 100644
index 00000000..858c0815
--- /dev/null
+++ b/packages/amino/src/pubkeys.spec.ts
@@ -0,0 +1,44 @@
+import { isSinglePubkey } from "./pubkeys";
+
+describe("pubkeys", () => {
+  const pubkeyEd25519 = {
+    type: "tendermint/PubKeyEd25519",
+    value: "YZHlYxP5R6olj3Tj3f7VgkQE5VaOvv9G0jKATqdQsqI=",
+  };
+  const pubkeySecp256k1 = {
+    type: "tendermint/PubKeySecp256k1",
+    value: "AtQaCqFnshaZQp6rIkvAPyzThvCvXSDO+9AzbxVErqJP",
+  };
+  const pubkeyMultisigThreshold = {
+    type: "tendermint/PubKeyMultisigThreshold",
+    value: {
+      threshold: "3",
+      pubkeys: [
+        {
+          type: "tendermint/PubKeySecp256k1",
+          value: "A4KZH7VSRwW/6RTExROivRYKsQP63LnGcBlXFo+eKGpQ",
+        },
+        {
+          type: "tendermint/PubKeySecp256k1",
+          value: "A8/Cq4VigOnDgl6RSdcx97fjrdCo/qwAX6C34n7ZDZLs",
+        },
+        {
+          type: "tendermint/PubKeySecp256k1",
+          value: "ApKgZuwy03xgdRnXqG6yEHATomsWDOPacy7nbpsuUCSS",
+        },
+        {
+          type: "tendermint/PubKeySecp256k1",
+          value: "Aptm8E3WSSFS0RTAIUW+bLi/slYnTEE+h4qPTG28CHfq",
+        },
+      ],
+    },
+  };
+
+  describe("isSinglePubkey", () => {
+    it("works", () => {
+      expect(isSinglePubkey(pubkeyEd25519)).toEqual(true);
+      expect(isSinglePubkey(pubkeySecp256k1)).toEqual(true);
+      expect(isSinglePubkey(pubkeyMultisigThreshold)).toEqual(false);
+    });
+  });
+});
diff --git a/packages/amino/src/pubkeys.ts b/packages/amino/src/pubkeys.ts
index 3036afcf..e538e657 100644
--- a/packages/amino/src/pubkeys.ts
+++ b/packages/amino/src/pubkeys.ts
@@ -1,10 +1,13 @@
-export interface PubKey {
+export interface Pubkey {
   // type is one of the strings defined in pubkeyType
   // I don't use a string literal union here as that makes trouble with json test data:
   // https://github.com/cosmos/cosmjs/pull/44#pullrequestreview-353280504
   readonly type: string;
-  // Value field is base64-encoded in all cases
-  // Note: if type is Secp256k1, this must contain a COMPRESSED pubkey - to encode from bcp/keycontrol land, you must compress it first
+  readonly value: any;
+}
+
+export interface Secp256k1Pubkey extends SinglePubkey {
+  readonly type: "tendermint/PubKeySecp256k1";
   readonly value: string;
 }
 
@@ -16,3 +19,26 @@ export const pubkeyType = {
   /** @see https://github.com/tendermint/tendermint/blob/v0.33.0/crypto/sr25519/codec.go#L12 */
   sr25519: "tendermint/PubKeySr25519" as const,
 };
+
+/**
+ * A pubkey which contains the data directly without further nesting.
+ *
+ * You can think of this as a non-multisig pubkey.
+ */
+export interface SinglePubkey extends Pubkey {
+  // type is one of the strings defined in pubkeyType
+  // I don't use a string literal union here as that makes trouble with json test data:
+  // https://github.com/cosmos/cosmjs/pull/44#pullrequestreview-353280504
+  readonly type: string;
+  /**
+   * The base64 encoding of the Amino binary encoded pubkey.
+   *
+   * Note: if type is Secp256k1, this must contain a 33 bytes compressed pubkey.
+   */
+  readonly value: string;
+}
+
+export function isSinglePubkey(pubkey: Pubkey): pubkey is SinglePubkey {
+  const singPubkeyTypes: string[] = [pubkeyType.ed25519, pubkeyType.secp256k1, pubkeyType.sr25519];
+  return singPubkeyTypes.includes(pubkey.type);
+}
diff --git a/packages/launchpad/src/address.ts b/packages/launchpad/src/address.ts
index a35b2a0e..adfc43a0 100644
--- a/packages/launchpad/src/address.ts
+++ b/packages/launchpad/src/address.ts
@@ -1,4 +1,4 @@
-import { PubKey, pubkeyType } from "@cosmjs/amino";
+import { pubkeyType, SinglePubkey } from "@cosmjs/amino";
 import { ripemd160, sha256 } from "@cosmjs/crypto";
 import { Bech32, fromBase64 } from "@cosmjs/encoding";
 
@@ -13,7 +13,7 @@ export function rawSecp256k1PubkeyToAddress(pubkeyRaw: Uint8Array, prefix: strin
 
 // See https://github.com/tendermint/tendermint/blob/f2ada0a604b4c0763bda2f64fac53d506d3beca7/docs/spec/blockchain/encoding.md#public-key-cryptography
 // This assumes we already have a cosmos-compressed pubkey
-export function pubkeyToAddress(pubkey: PubKey, prefix: string): string {
+export function pubkeyToAddress(pubkey: SinglePubkey, prefix: string): string {
   const pubkeyBytes = fromBase64(pubkey.value);
   switch (pubkey.type) {
     case pubkeyType.secp256k1: {
diff --git a/packages/launchpad/src/cosmosclient.ts b/packages/launchpad/src/cosmosclient.ts
index d49e018b..9bb2764e 100644
--- a/packages/launchpad/src/cosmosclient.ts
+++ b/packages/launchpad/src/cosmosclient.ts
@@ -1,4 +1,4 @@
-import { PubKey } from "@cosmjs/amino";
+import { Pubkey } from "@cosmjs/amino";
 import { sha256 } from "@cosmjs/crypto";
 import { fromBase64, fromHex, toHex } from "@cosmjs/encoding";
 import { Uint53 } from "@cosmjs/math";
@@ -24,7 +24,7 @@ export interface Account {
   /** Bech32 account address */
   readonly address: string;
   readonly balance: readonly Coin[];
-  readonly pubkey: PubKey | undefined;
+  readonly pubkey: Pubkey | undefined;
   readonly accountNumber: number;
   readonly sequence: number;
 }
diff --git a/packages/launchpad/src/index.ts b/packages/launchpad/src/index.ts
index 46b2e770..ea1120b5 100644
--- a/packages/launchpad/src/index.ts
+++ b/packages/launchpad/src/index.ts
@@ -6,7 +6,7 @@ export {
   encodeBech32Pubkey,
   encodeSecp256k1Pubkey,
   pubkeyType,
-  PubKey,
+  SinglePubkey as PubKey,
 } from "@cosmjs/amino";
 
 import * as logs from "./logs";
diff --git a/packages/launchpad/src/lcdapi/auth.ts b/packages/launchpad/src/lcdapi/auth.ts
index 009c91ba..947ff1da 100644
--- a/packages/launchpad/src/lcdapi/auth.ts
+++ b/packages/launchpad/src/lcdapi/auth.ts
@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/naming-convention */
-import { PubKey } from "@cosmjs/amino";
+import { Pubkey } from "@cosmjs/amino";
 
 import { Coin } from "../coins";
 import { LcdClient } from "./lcdclient";
@@ -26,7 +26,7 @@ export interface BaseAccount {
    * [1]: https://github.com/cosmos/cosmos-sdk/pull/5280
    * [2]: https://github.com/cosmos/cosmos-sdk/pull/6749
    */
-  readonly public_key: string | PubKey | null;
+  readonly public_key: string | Pubkey | null;
   /**
    * The account number assigned by the blockchain.
    *
diff --git a/packages/launchpad/src/lcdapi/utils.spec.ts b/packages/launchpad/src/lcdapi/utils.spec.ts
index 848ea00c..646eee1c 100644
--- a/packages/launchpad/src/lcdapi/utils.spec.ts
+++ b/packages/launchpad/src/lcdapi/utils.spec.ts
@@ -1,4 +1,4 @@
-import { PubKey } from "@cosmjs/amino";
+import { Pubkey } from "@cosmjs/amino";
 
 import { normalizePubkey, uint64ToNumber, uint64ToString } from "./utils";
 
@@ -85,7 +85,7 @@ describe("utils", () => {
     });
 
     it("passes PubKey unchanged", () => {
-      const original: PubKey = {
+      const original: Pubkey = {
         type: "tendermint/PubKeySecp256k1",
         value: "A08EGB7ro1ORuFhjOnZcSgwYlpe0DSFjVNUIkNNQxwKQ",
       };
diff --git a/packages/launchpad/src/lcdapi/utils.ts b/packages/launchpad/src/lcdapi/utils.ts
index 1fd35af3..558033dc 100644
--- a/packages/launchpad/src/lcdapi/utils.ts
+++ b/packages/launchpad/src/lcdapi/utils.ts
@@ -1,4 +1,4 @@
-import { decodeBech32Pubkey, PubKey } from "@cosmjs/amino";
+import { decodeBech32Pubkey, Pubkey } from "@cosmjs/amino";
 import { Uint64 } from "@cosmjs/math";
 
 /**
@@ -29,7 +29,7 @@ export function uint64ToString(input: number | string): string {
  *
  * Returns null when unset.
  */
-export function normalizePubkey(input: string | PubKey | null): PubKey | null {
+export function normalizePubkey(input: string | Pubkey | null): Pubkey | null {
   if (!input) return null;
   if (typeof input === "string") return decodeBech32Pubkey(input);
   return input;
diff --git a/packages/launchpad/src/types.ts b/packages/launchpad/src/types.ts
index 7cccf774..bb674bc1 100644
--- a/packages/launchpad/src/types.ts
+++ b/packages/launchpad/src/types.ts
@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/naming-convention */
-import { PubKey } from "@cosmjs/amino";
+import { Pubkey } from "@cosmjs/amino";
 
 import { Coin } from "./coins";
 
@@ -9,6 +9,6 @@ export interface StdFee {
 }
 
 export interface StdSignature {
-  readonly pub_key: PubKey;
+  readonly pub_key: Pubkey;
   readonly signature: string;
 }
diff --git a/packages/proto-signing/src/pubkey.ts b/packages/proto-signing/src/pubkey.ts
index e44d3b80..faa88ac4 100644
--- a/packages/proto-signing/src/pubkey.ts
+++ b/packages/proto-signing/src/pubkey.ts
@@ -1,5 +1,5 @@
 /* eslint-disable @typescript-eslint/naming-convention */
-import { encodeSecp256k1Pubkey, PubKey as AminoPubKey } from "@cosmjs/amino";
+import { encodeSecp256k1Pubkey, SinglePubkey as AminoPubKey } from "@cosmjs/amino";
 import { fromBase64 } from "@cosmjs/encoding";
 
 import { PubKey } from "./codec/cosmos/crypto/secp256k1/keys";
diff --git a/packages/stargate/src/accounts.ts b/packages/stargate/src/accounts.ts
index e6594b35..04ab739b 100644
--- a/packages/stargate/src/accounts.ts
+++ b/packages/stargate/src/accounts.ts
@@ -1,4 +1,4 @@
-import { PubKey } from "@cosmjs/amino";
+import { Pubkey } from "@cosmjs/amino";
 import { Uint64 } from "@cosmjs/math";
 import { decodePubkey } from "@cosmjs/proto-signing";
 import { assert } from "@cosmjs/utils";
@@ -16,7 +16,7 @@ import { Any } from "./codec/google/protobuf/any";
 export interface Account {
   /** Bech32 account address */
   readonly address: string;
-  readonly pubkey: PubKey | null;
+  readonly pubkey: Pubkey | null;
   readonly accountNumber: number;
   readonly sequence: number;
 }