diff --git a/src/activitypub/authentication.rs b/src/activitypub/authentication.rs
index 64a5443..d616bb2 100644
--- a/src/activitypub/authentication.rs
+++ b/src/activitypub/authentication.rs
@@ -13,6 +13,7 @@ use crate::identity::did::Did;
 use crate::json_signatures::verify::{
     get_json_signature,
     verify_eip191_json_signature,
+    verify_minisign_json_signature,
     verify_rsa_json_signature,
     JsonSignatureVerificationError as JsonSignatureError,
     JsonSigner,
@@ -137,8 +138,7 @@ pub async fn verify_signed_activity(
             verify_rsa_json_signature(&signature_data, &public_key)?;
             actor_profile
         },
-        JsonSigner::DidPkh(did_pkh) => {
-            let did = Did::Pkh(did_pkh.clone());
+        JsonSigner::Did(did) => {
             let mut profiles: Vec<_> = search_profiles_by_did_only(db_client, &did)
                 .await?.into_iter()
                 // Exclude local profiles
@@ -151,11 +151,22 @@ pub async fn verify_signed_activity(
                 );
             };
             if let Some(profile) = profiles.pop() {
-                verify_eip191_json_signature(
-                    &did_pkh,
-                    &signature_data.message,
-                    &signature_data.signature,
-                )?;
+                match did {
+                    Did::Key(did_key) => {
+                        verify_minisign_json_signature(
+                            &did_key,
+                            &signature_data.message,
+                            &signature_data.signature,
+                        )?;
+                    },
+                    Did::Pkh(did_pkh) => {
+                        verify_eip191_json_signature(
+                            &did_pkh,
+                            &signature_data.message,
+                            &signature_data.signature,
+                        )?;
+                    },
+                };
                 profile
             } else {
                 return Err(AuthenticationError::ActorError("unknown signer".to_string()));
diff --git a/src/identity/signatures.rs b/src/identity/signatures.rs
index 1b2bce1..80facbe 100644
--- a/src/identity/signatures.rs
+++ b/src/identity/signatures.rs
@@ -14,3 +14,6 @@ pub const PROOF_TYPE_JCS_RSA: &str = "JcsRsaSignature2022";
 
 // Similar to EthereumPersonalSignature2021 but with JCS
 pub const PROOF_TYPE_JCS_EIP191: &str ="JcsEip191Signature2022";
+
+// Version 2022A
+pub const PROOF_TYPE_JCS_MINISIGN: &str = "MitraJcsMinisignSignature2022A";
diff --git a/src/json_signatures/create.rs b/src/json_signatures/create.rs
index e49b374..c475c6f 100644
--- a/src/json_signatures/create.rs
+++ b/src/json_signatures/create.rs
@@ -4,8 +4,13 @@ use serde::{Deserialize, Serialize};
 use serde_json::Value;
 
 use crate::identity::{
+    did_key::DidKey,
     did_pkh::DidPkh,
-    signatures::{PROOF_TYPE_JCS_EIP191, PROOF_TYPE_JCS_RSA},
+    signatures::{
+        PROOF_TYPE_JCS_EIP191,
+        PROOF_TYPE_JCS_MINISIGN,
+        PROOF_TYPE_JCS_RSA,
+    },
 };
 use crate::utils::canonicalization::{
     canonicalize_object,
@@ -55,6 +60,19 @@ impl IntegrityProof {
             proof_value: signature.to_string(),
         }
     }
+
+    pub fn jcs_minisign(
+        signer: &DidKey,
+        signature: &str,
+    ) -> Self {
+        Self {
+            proof_type: PROOF_TYPE_JCS_MINISIGN.to_string(),
+            proof_purpose: PROOF_PURPOSE.to_string(),
+            verification_method: signer.to_string(),
+            created: Utc::now(),
+            proof_value: signature.to_string(),
+        }
+    }
 }
 
 #[derive(thiserror::Error, Debug)]
diff --git a/src/json_signatures/verify.rs b/src/json_signatures/verify.rs
index c3e8ae7..0411990 100644
--- a/src/json_signatures/verify.rs
+++ b/src/json_signatures/verify.rs
@@ -3,8 +3,15 @@ use serde_json::Value;
 
 use crate::ethereum::identity::verify_eip191_signature;
 use crate::identity::{
+    did::Did,
+    did_key::DidKey,
     did_pkh::DidPkh,
-    signatures::{PROOF_TYPE_JCS_EIP191, PROOF_TYPE_JCS_RSA},
+    minisign::verify_minisign_signature,
+    signatures::{
+        PROOF_TYPE_JCS_EIP191,
+        PROOF_TYPE_JCS_MINISIGN,
+        PROOF_TYPE_JCS_RSA,
+    },
 };
 use crate::utils::canonicalization::{
     canonicalize_object,
@@ -20,7 +27,7 @@ use super::create::{
 #[derive(Debug, PartialEq)]
 pub enum JsonSigner {
     ActorKeyId(String),
-    DidPkh(DidPkh),
+    Did(Did),
 }
 
 pub struct SignatureData {
@@ -67,9 +74,14 @@ pub fn get_json_signature(
     };
     let signer = match proof.proof_type.as_str() {
         PROOF_TYPE_JCS_EIP191 => {
-            let did = proof.verification_method.parse()
+            let did_pkh: DidPkh = proof.verification_method.parse()
                 .map_err(|_| VerificationError::InvalidProof("invalid DID"))?;
-            JsonSigner::DidPkh(did)
+            JsonSigner::Did(Did::Pkh(did_pkh))
+        },
+        PROOF_TYPE_JCS_MINISIGN => {
+            let did_key: DidKey = proof.verification_method.parse()
+                .map_err(|_| VerificationError::InvalidProof("invalid DID"))?;
+            JsonSigner::Did(Did::Key(did_key))
         },
         PROOF_TYPE_JCS_RSA => {
             JsonSigner::ActorKeyId(proof.verification_method)
@@ -111,6 +123,15 @@ pub fn verify_eip191_json_signature(
         .map_err(|_| VerificationError::InvalidSignature)
 }
 
+pub fn verify_minisign_json_signature(
+    signer: &DidKey,
+    message: &str,
+    signature: &str,
+) -> Result<(), VerificationError> {
+    verify_minisign_signature(signer, message, signature)
+        .map_err(|_| VerificationError::InvalidSignature)
+}
+
 #[cfg(test)]
 mod tests {
     use serde_json::json;
@@ -133,10 +154,10 @@ mod tests {
             },
         });
         let signature_data = get_json_signature(&signed_object).unwrap();
-        let expected_signer = JsonSigner::DidPkh(DidPkh::from_address(
+        let expected_signer = JsonSigner::Did(Did::Pkh(DidPkh::from_address(
             &Currency::Ethereum,
             "0xb9c5714089478a327f09197987f16f9e5d936e8a",
-        ));
+        )));
         assert_eq!(signature_data.signer, expected_signer);
         assert_eq!(signature_data.signature, "xxx");
     }
diff --git a/src/mastodon_api/accounts/views.rs b/src/mastodon_api/accounts/views.rs
index a5ab54d..ed4ea7e 100644
--- a/src/mastodon_api/accounts/views.rs
+++ b/src/mastodon_api/accounts/views.rs
@@ -33,7 +33,10 @@ use crate::identity::{
 };
 use crate::json_signatures::{
     create::{add_integrity_proof, IntegrityProof},
-    verify::verify_eip191_json_signature,
+    verify::{
+        verify_eip191_json_signature,
+        verify_minisign_json_signature,
+    },
 };
 use crate::mastodon_api::oauth::auth::get_current_user;
 use crate::mastodon_api::pagination::get_paginated_response;
@@ -267,7 +270,11 @@ async fn send_signed_update(
     let canonical_json = canonicalize_object(&activity)
         .map_err(|_| HttpError::InternalError)?;
     let proof = match signer {
-        Did::Key(_) => return Err(ValidationError("unsupported DID type").into()),
+        Did::Key(signer) => {
+            verify_minisign_json_signature(&signer, &canonical_json, &data.signature)
+                .map_err(|_| ValidationError("invalid signature"))?;
+            IntegrityProof::jcs_minisign(&signer, &data.signature)
+        },
         Did::Pkh(signer) => {
             verify_eip191_json_signature(&signer, &canonical_json, &data.signature)
                 .map_err(|_| ValidationError("invalid signature"))?;