diff --git a/ruma-client-api/CHANGELOG.md b/ruma-client-api/CHANGELOG.md
index c04a9e47..4ba3f3d9 100644
--- a/ruma-client-api/CHANGELOG.md
+++ b/ruma-client-api/CHANGELOG.md
@@ -50,6 +50,8 @@ Breaking changes:
 * Update strum dependency to 0.19
 * Rename `r0::message::{create_message_event => send_message_event}`
 * Rename `r0::state::{create_state_event_* => send_state_event_*}`
+* Replace `r0::keys::{AlgorithmAndDeviceId, KeyAlgorithm}` with
+  `ruma_identifiers::{DeviceKeyId, DeviceKeyAlgorithm}`, respectively
 
 Improvements:
 
diff --git a/ruma-client-api/src/r0/backup.rs b/ruma-client-api/src/r0/backup.rs
index 600f8660..7d84a2a7 100644
--- a/ruma-client-api/src/r0/backup.rs
+++ b/ruma-client-api/src/r0/backup.rs
@@ -8,12 +8,10 @@ pub mod get_latest_backup;
 pub mod update_backup;
 
 use js_int::UInt;
-use ruma_identifiers::UserId;
+use ruma_identifiers::{DeviceKeyId, UserId};
 use serde::{Deserialize, Serialize};
 use std::collections::BTreeMap;
 
-use crate::r0::keys::AlgorithmAndDeviceId;
-
 // TODO: remove
 /// A wrapper around a mapping of session IDs to key data.
 #[cfg(feature = "unstable-synapse-quirks")]
@@ -33,7 +31,7 @@ pub enum BackupAlgorithm {
         /// The curve25519 public key used to encrypt the backups, encoded in unpadded base64.
         public_key: String,
         /// Signatures of the auth_data as Signed JSON.
-        signatures: BTreeMap<UserId, BTreeMap<AlgorithmAndDeviceId, String>>,
+        signatures: BTreeMap<UserId, BTreeMap<DeviceKeyId, String>>,
     },
 }
 
diff --git a/ruma-client-api/src/r0/keys.rs b/ruma-client-api/src/r0/keys.rs
index 3f82ab9e..b1bb765c 100644
--- a/ruma-client-api/src/r0/keys.rs
+++ b/ruma-client-api/src/r0/keys.rs
@@ -1,17 +1,10 @@
 //! Endpoints for key management
 
-use std::{
-    collections::BTreeMap,
-    convert::TryFrom,
-    fmt::{self, Debug, Display, Formatter},
-};
+use std::{collections::BTreeMap, fmt::Debug};
 
 use ruma_events::Algorithm;
-use ruma_identifiers::{DeviceId, UserId};
-use serde::{
-    de::{self, Unexpected},
-    Deserialize, Deserializer, Serialize, Serializer,
-};
+use ruma_identifiers::{DeviceId, DeviceKeyId, UserId};
+use serde::{Deserialize, Serialize};
 
 pub mod claim_keys;
 pub mod get_key_changes;
@@ -23,98 +16,6 @@ pub mod upload_signatures;
 #[cfg(feature = "unstable-pre-spec")]
 pub mod upload_signing_keys;
 
-/// The basic key algorithms in the specification
-#[derive(Debug, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Serialize, Deserialize)]
-pub enum KeyAlgorithm {
-    /// The Ed25519 signature algorithm.
-    #[serde(rename = "ed25519")]
-    Ed25519,
-
-    /// The Curve25519 ECDH algorithm.
-    #[serde(rename = "curve25519")]
-    Curve25519,
-
-    /// The Curve25519 ECDH algorithm, but the key also contains signatures
-    #[serde(rename = "signed_curve25519")]
-    SignedCurve25519,
-}
-
-impl Display for KeyAlgorithm {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        let algorithm_str = match *self {
-            KeyAlgorithm::Ed25519 => "ed25519",
-            KeyAlgorithm::Curve25519 => "curve25519",
-            KeyAlgorithm::SignedCurve25519 => "signed_curve25519",
-        };
-        write!(f, "{}", algorithm_str)?;
-        Ok(())
-    }
-}
-
-impl TryFrom<&'_ str> for KeyAlgorithm {
-    type Error = &'static str;
-    fn try_from(s: &str) -> Result<Self, Self::Error> {
-        match s {
-            "ed25519" => Ok(KeyAlgorithm::Ed25519),
-            "curve25519" => Ok(KeyAlgorithm::Curve25519),
-            "signed_curve25519" => Ok(KeyAlgorithm::SignedCurve25519),
-            _ => Err("Unknown algorithm"),
-        }
-    }
-}
-
-/// A key algorithm and a device id, combined with a ':'
-#[derive(Debug, Clone, PartialEq, Eq, PartialOrd, Ord)]
-pub struct AlgorithmAndDeviceId(pub KeyAlgorithm, pub Box<DeviceId>);
-
-impl Display for AlgorithmAndDeviceId {
-    fn fmt(&self, f: &mut Formatter<'_>) -> fmt::Result {
-        write!(f, "{}:{}", self.0, self.1)
-    }
-}
-
-impl Serialize for AlgorithmAndDeviceId {
-    fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-    where
-        S: Serializer,
-    {
-        serializer.serialize_str(&self.to_string())
-    }
-}
-
-impl<'de> Deserialize<'de> for AlgorithmAndDeviceId {
-    #[allow(clippy::comparison_chain)]
-    fn deserialize<D>(deserializer: D) -> Result<Self, D::Error>
-    where
-        D: Deserializer<'de>,
-    {
-        let value = String::deserialize(deserializer)?;
-        let parts = value.split(':').collect::<Vec<_>>();
-
-        const EXPECTED: &str = "a string composed of an algorithm and a device id separated by ':'";
-
-        if parts.len() < 2 {
-            return Err(de::Error::invalid_type(
-                Unexpected::Other("string without a ':' separator"),
-                &EXPECTED,
-            ));
-        } else if parts.len() > 2 {
-            return Err(de::Error::invalid_type(
-                Unexpected::Other("string with more than one ':' separator"),
-                &EXPECTED,
-            ));
-        }
-
-        let algorithm_result = KeyAlgorithm::try_from(parts[0]);
-        match algorithm_result {
-            Ok(algorithm) => Ok(AlgorithmAndDeviceId(algorithm, parts[1].into())),
-            Err(_) => {
-                Err(de::Error::invalid_value(Unexpected::Str(parts[0]), &"valid key algorithm"))
-            }
-        }
-    }
-}
-
 /// Identity keys for a device.
 #[derive(Debug, Clone, Serialize, Deserialize)]
 pub struct DeviceKeys {
@@ -128,10 +29,10 @@ pub struct DeviceKeys {
     pub algorithms: Vec<Algorithm>,
 
     /// Public identity keys.
-    pub keys: BTreeMap<AlgorithmAndDeviceId, String>,
+    pub keys: BTreeMap<DeviceKeyId, String>,
 
     /// Signatures for the device key object.
-    pub signatures: BTreeMap<UserId, BTreeMap<AlgorithmAndDeviceId, String>>,
+    pub signatures: BTreeMap<UserId, BTreeMap<DeviceKeyId, String>>,
 
     /// Additional data added to the device key information by intermediate servers, and
     /// not covered by the signatures.
@@ -153,7 +54,7 @@ pub struct SignedKey {
     pub key: String,
 
     /// Signatures for the key object.
-    pub signatures: BTreeMap<UserId, BTreeMap<AlgorithmAndDeviceId, String>>,
+    pub signatures: BTreeMap<UserId, BTreeMap<DeviceKeyId, String>>,
 }
 
 /// A one-time public key for "pre-key" messages.
diff --git a/ruma-client-api/src/r0/keys/claim_keys.rs b/ruma-client-api/src/r0/keys/claim_keys.rs
index 4cd08281..0b5f2bd9 100644
--- a/ruma-client-api/src/r0/keys/claim_keys.rs
+++ b/ruma-client-api/src/r0/keys/claim_keys.rs
@@ -1,14 +1,14 @@
-//! [POST /_matrix/client/r0/keys/claim](https://matrix.org/docs/spec/client_server/r0.6.0#post-matrix-client-r0-keys-claim)
+//! [POST /_matrix/client/r0/keys/claim](https://matrix.org/docs/spec/client_server/r0.6.1#post-matrix-client-r0-keys-claim)
 
 use std::collections::BTreeMap;
 
 use std::time::Duration;
 
 use ruma_api::ruma_api;
-use ruma_identifiers::{DeviceId, UserId};
+use ruma_identifiers::{DeviceId, DeviceKeyAlgorithm, DeviceKeyId, UserId};
 use serde_json::Value as JsonValue;
 
-use super::{AlgorithmAndDeviceId, KeyAlgorithm, OneTimeKey};
+use super::OneTimeKey;
 
 ruma_api! {
     metadata: {
@@ -31,7 +31,7 @@ ruma_api! {
         pub timeout: Option<Duration>,
 
         /// The keys to be claimed.
-        pub one_time_keys: BTreeMap<UserId, BTreeMap<Box<DeviceId>, KeyAlgorithm>>,
+        pub one_time_keys: BTreeMap<UserId, BTreeMap<Box<DeviceId>, DeviceKeyAlgorithm>>,
     }
 
     response: {
@@ -47,4 +47,4 @@ ruma_api! {
 }
 
 /// The one-time keys for a given device.
-pub type OneTimeKeys = BTreeMap<Box<DeviceId>, BTreeMap<AlgorithmAndDeviceId, OneTimeKey>>;
+pub type OneTimeKeys = BTreeMap<Box<DeviceId>, BTreeMap<DeviceKeyId, OneTimeKey>>;
diff --git a/ruma-client-api/src/r0/keys/upload_keys.rs b/ruma-client-api/src/r0/keys/upload_keys.rs
index 0d649bde..43684808 100644
--- a/ruma-client-api/src/r0/keys/upload_keys.rs
+++ b/ruma-client-api/src/r0/keys/upload_keys.rs
@@ -4,8 +4,9 @@ use std::collections::BTreeMap;
 
 use js_int::UInt;
 use ruma_api::ruma_api;
+use ruma_identifiers::{DeviceKeyAlgorithm, DeviceKeyId};
 
-use super::{AlgorithmAndDeviceId, DeviceKeys, KeyAlgorithm, OneTimeKey};
+use super::{DeviceKeys, OneTimeKey};
 
 ruma_api! {
     metadata: {
@@ -24,13 +25,13 @@ ruma_api! {
 
         /// One-time public keys for "pre-key" messages.
         #[serde(skip_serializing_if = "Option::is_none")]
-        pub one_time_keys: Option<BTreeMap<AlgorithmAndDeviceId, OneTimeKey>>,
+        pub one_time_keys: Option<BTreeMap<DeviceKeyId, OneTimeKey>>,
     }
 
     response: {
         /// For each key algorithm, the number of unclaimed one-time keys of that
         /// type currently held on the server for this device.
-        pub one_time_key_counts: BTreeMap<KeyAlgorithm, UInt>
+        pub one_time_key_counts: BTreeMap<DeviceKeyAlgorithm, UInt>
     }
 
     error: crate::Error
diff --git a/ruma-client-api/src/r0/sync/sync_events.rs b/ruma-client-api/src/r0/sync/sync_events.rs
index e0a28dfa..8450fd28 100644
--- a/ruma-client-api/src/r0/sync/sync_events.rs
+++ b/ruma-client-api/src/r0/sync/sync_events.rs
@@ -9,10 +9,10 @@ use ruma_events::{
     presence::PresenceEvent, AnyBasicEvent, AnyStrippedStateEvent, AnySyncEphemeralRoomEvent,
     AnySyncRoomEvent, AnySyncStateEvent, AnyToDeviceEvent,
 };
-use ruma_identifiers::{RoomId, UserId};
+use ruma_identifiers::{DeviceKeyAlgorithm, RoomId, UserId};
 use serde::{Deserialize, Serialize};
 
-use crate::r0::{filter::FilterDefinition, keys::KeyAlgorithm};
+use crate::r0::filter::FilterDefinition;
 
 ruma_api! {
     metadata: {
@@ -87,7 +87,7 @@ ruma_api! {
         /// For each key algorithm, the number of unclaimed one-time keys
         /// currently held on the server for a device.
         #[serde(default, skip_serializing_if = "BTreeMap::is_empty")]
-        pub device_one_time_keys_count: BTreeMap<KeyAlgorithm, UInt>,
+        pub device_one_time_keys_count: BTreeMap<DeviceKeyAlgorithm, UInt>,
     }
 
     error: crate::Error