diff --git a/src/appstate.rs b/src/appstate.rs
index db76e68..b3a080a 100644
--- a/src/appstate.rs
+++ b/src/appstate.rs
@@ -9,7 +9,7 @@ use crate::{
     error,
     file::{Chunk, FileTrait},
     output::new_progressbar,
-    sharry::Client,
+    sharry::{Client, ShareID},
 };
 
 pub struct AppState {
@@ -33,7 +33,7 @@ fn new_http(args: &Cli) -> ureq::Agent {
         .into()
 }
 
-fn new_share(args: &Cli) -> error::Result<String> {
+fn new_share(args: &Cli) -> error::Result<ShareID> {
     new_http(args).share_create(&args.get_uri(), &args.alias, args.get_share_request())
 }
 
diff --git a/src/cachefile.rs b/src/cachefile.rs
index 9d0dba3..6ce65bd 100644
--- a/src/cachefile.rs
+++ b/src/cachefile.rs
@@ -15,7 +15,7 @@ use crate::{
     error,
     file::{self, Chunk, FileTrait},
     output::new_progressbar,
-    sharry::{Client, Uri},
+    sharry::{AliasID, Client, ShareID, Uri},
 };
 
 #[derive(Serialize, Deserialize, Debug)]
@@ -24,8 +24,8 @@ pub struct CacheFile {
     file_name: PathBuf,
 
     uri: Uri,
-    alias_id: String,
-    share_id: String,
+    alias_id: AliasID,
+    share_id: ShareID,
 
     uploading: Option<file::Uploading>,
     files: VecDeque<file::Checked>,
@@ -98,7 +98,7 @@ impl CacheFile {
 
     pub fn from_args(
         args: &Cli,
-        new_share: impl FnOnce(&Cli) -> error::Result<String>,
+        new_share: impl FnOnce(&Cli) -> error::Result<ShareID>,
     ) -> error::Result<Self> {
         let mut files = args.files.clone();
 
diff --git a/src/cli.rs b/src/cli.rs
index 491be5d..5b5f3c8 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -11,7 +11,7 @@ use log::LevelFilter;
 
 use crate::{
     file::{Checked, FileTrait},
-    sharry::{NewShareRequest, Uri},
+    sharry::{AliasID, NewShareRequest, Uri},
 };
 
 #[derive(Parser)]
@@ -69,7 +69,7 @@ pub struct Cli {
     url: String,
 
     /// ID of a public alias to use
-    pub alias: String,
+    pub alias: AliasID,
 
     /// Files to upload to the new share
     #[arg(value_name = "FILE", required = true, value_parser = parse_sharry_file)]
@@ -159,7 +159,7 @@ impl Cli {
         let mut hasher = Blake2b::new().hash_length(16).to_state();
 
         hasher.update(self.get_uri().as_ref());
-        hasher.update(self.alias.as_bytes());
+        hasher.update(self.alias.as_ref());
 
         for chk in sorted(&self.files) {
             hasher.update(chk.as_ref());
diff --git a/src/error.rs b/src/error.rs
index ffbe246..d708d96 100644
--- a/src/error.rs
+++ b/src/error.rs
@@ -8,10 +8,10 @@ pub enum Parameter {
     Uri(String),
 
     #[error("given Alias ID {0:?}")]
-    AliasID(String),
+    AliasID(sharry::AliasID),
 
     #[error("stored Share ID {0:?}")]
-    ShareID(String),
+    ShareID(sharry::ShareID),
 
     #[error("stored {0:?}")]
     FileID(sharry::FileID),
diff --git a/src/file/checked.rs b/src/file/checked.rs
index 92e9ef7..e5c8fc5 100644
--- a/src/file/checked.rs
+++ b/src/file/checked.rs
@@ -76,8 +76,8 @@ impl Checked {
         self,
         client: &impl sharry::Client,
         uri: &sharry::Uri,
-        alias_id: &str,
-        share_id: &str,
+        alias_id: &sharry::AliasID,
+        share_id: &sharry::ShareID,
     ) -> error::Result<Uploading> {
         let file_id = client.file_create(uri, alias_id, share_id, &self)?;
 
diff --git a/src/impl_ureq.rs b/src/impl_ureq.rs
index 0a2721c..2e50a8b 100644
--- a/src/impl_ureq.rs
+++ b/src/impl_ureq.rs
@@ -3,13 +3,13 @@ use log::{debug, trace};
 use crate::{
     error,
     file::{self, FileTrait},
-    sharry::{self, FileID, Uri},
+    sharry::{self, AliasID, FileID, ShareID, Uri},
 };
 
 fn find_cause(
     uri: &Uri,
-    alias_id: &str,
-    share_id: Option<&str>,
+    alias_id: &AliasID,
+    share_id: Option<&ShareID>,
     file_id: Option<&FileID>,
 ) -> impl FnOnce(ureq::Error) -> error::Error {
     move |error| match error {
@@ -22,7 +22,7 @@ fn find_cause(
             trace!("HTTP Error 404: Share and/or file may have been deleted!");
 
             if let Some(file_id) = file_id {
-                error::Error::InvalidParameter(error::Parameter::FileID(file_id.clone()))
+                error::Error::InvalidParameter(error::Parameter::FileID(file_id.to_owned()))
             } else if let Some(share_id) = share_id {
                 error::Error::InvalidParameter(error::Parameter::ShareID(share_id.to_owned()))
             } else {
@@ -50,15 +50,15 @@ impl sharry::Client for ureq::Agent {
     fn share_create(
         &self,
         uri: &Uri,
-        alias_id: &str,
+        alias_id: &AliasID,
         data: sharry::NewShareRequest,
-    ) -> error::Result<String> {
+    ) -> error::Result<ShareID> {
         let res = {
             let endpoint = uri.share_create();
 
             let mut res = self
                 .post(&endpoint)
-                .header("Sharry-Alias", alias_id)
+                .header("Sharry-Alias", alias_id.as_ref())
                 .send_json(data)
                 .map_err(find_cause(uri, alias_id, None, None))?;
 
@@ -75,19 +75,19 @@ impl sharry::Client for ureq::Agent {
         if res.success && (res.message == "Share created.") {
             trace!("new share id: {:?}", res.id);
 
-            Ok(res.id)
+            Ok(res.id.into())
         } else {
             Err(error::Error::response(format!("{res:?}")))
         }
     }
 
-    fn share_notify(&self, uri: &Uri, alias_id: &str, share_id: &str) -> error::Result<()> {
+    fn share_notify(&self, uri: &Uri, alias_id: &AliasID, share_id: &ShareID) -> error::Result<()> {
         let res = {
             let endpoint = uri.share_notify(share_id);
 
             let mut res = self
                 .post(&endpoint)
-                .header("Sharry-Alias", alias_id)
+                .header("Sharry-Alias", alias_id.as_ref())
                 .send_empty()
                 .map_err(find_cause(uri, alias_id, Some(share_id), None))?;
 
@@ -107,8 +107,8 @@ impl sharry::Client for ureq::Agent {
     fn file_create(
         &self,
         uri: &Uri,
-        alias_id: &str,
-        share_id: &str,
+        alias_id: &AliasID,
+        share_id: &ShareID,
         file: &file::Checked,
     ) -> error::Result<FileID> {
         let res = {
@@ -116,7 +116,7 @@ impl sharry::Client for ureq::Agent {
 
             let res = self
                 .post(&endpoint)
-                .header("Sharry-Alias", alias_id)
+                .header("Sharry-Alias", alias_id.as_ref())
                 .header("Sharry-File-Name", file.get_name())
                 .header("Upload-Length", file.get_size())
                 .send_empty()
@@ -139,8 +139,8 @@ impl sharry::Client for ureq::Agent {
     fn file_patch(
         &self,
         uri: &Uri,
-        alias_id: &str,
-        share_id: &str,
+        alias_id: &AliasID,
+        share_id: &ShareID,
         chunk: &file::Chunk,
     ) -> error::Result<()> {
         let res = {
@@ -148,7 +148,7 @@ impl sharry::Client for ureq::Agent {
 
             let res = self
                 .patch(&endpoint)
-                .header("Sharry-Alias", alias_id)
+                .header("Sharry-Alias", alias_id.as_ref())
                 .header("Upload-Offset", chunk.get_offset())
                 .send(chunk.get_data())
                 .map_err(find_cause(
diff --git a/src/sharry/api/id.rs b/src/sharry/api/id.rs
index a951f82..cd4d6a3 100644
--- a/src/sharry/api/id.rs
+++ b/src/sharry/api/id.rs
@@ -6,8 +6,41 @@ use serde::{Deserialize, Serialize};
 
 use crate::error;
 
-// pub struct AliasID(String);
-// pub struct ShareID(String);
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct AliasID(String);
+
+impl fmt::Display for AliasID {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+impl AsRef<[u8]> for AliasID {
+    fn as_ref(&self) -> &[u8] {
+        self.0.as_bytes()
+    }
+}
+
+impl From<String> for AliasID {
+    fn from(value: String) -> Self {
+        Self(value)
+    }
+}
+
+#[derive(Serialize, Deserialize, Debug, Clone)]
+pub struct ShareID(String);
+
+impl fmt::Display for ShareID {
+    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
+        f.write_str(&self.0)
+    }
+}
+
+impl From<String> for ShareID {
+    fn from(value: String) -> Self {
+        Self(value)
+    }
+}
 
 #[derive(Serialize, Deserialize, Debug, Clone)]
 pub struct FileID(String);
diff --git a/src/sharry/api/mod.rs b/src/sharry/api/mod.rs
index 5e17abf..b272b6b 100644
--- a/src/sharry/api/mod.rs
+++ b/src/sharry/api/mod.rs
@@ -2,6 +2,6 @@ mod id;
 mod json;
 mod uri;
 
-pub use id::FileID;
+pub use id::{AliasID, FileID, ShareID};
 pub use json::{NewShareRequest, NewShareResponse, NotifyShareResponse};
 pub use uri::Uri;
diff --git a/src/sharry/api/uri.rs b/src/sharry/api/uri.rs
index e3c0c5f..ea3e647 100644
--- a/src/sharry/api/uri.rs
+++ b/src/sharry/api/uri.rs
@@ -33,15 +33,15 @@ impl Uri {
         self.endpoint(format_args!("alias/upload/new"))
     }
 
-    pub fn share_notify(&self, share_id: &str) -> String {
+    pub fn share_notify(&self, share_id: &super::ShareID) -> String {
         self.endpoint(format_args!("alias/mail/notify/{share_id}"))
     }
 
-    pub fn file_create(&self, share_id: &str) -> String {
+    pub fn file_create(&self, share_id: &super::ShareID) -> String {
         self.endpoint(format_args!("alias/upload/{share_id}/files/tus"))
     }
 
-    pub fn file_patch(&self, share_id: &str, file_id: &super::FileID) -> String {
+    pub fn file_patch(&self, share_id: &super::ShareID, file_id: &super::FileID) -> String {
         self.endpoint(format_args!("alias/upload/{share_id}/files/tus/{file_id}"))
     }
 }
diff --git a/src/sharry/client.rs b/src/sharry/client.rs
index 8d45f40..5cf3e30 100644
--- a/src/sharry/client.rs
+++ b/src/sharry/client.rs
@@ -1,30 +1,33 @@
 use crate::{error, file};
 
-use super::api::{FileID, NewShareRequest, Uri};
+use super::{
+    AliasID, ShareID,
+    api::{FileID, NewShareRequest, Uri},
+};
 
 pub trait Client {
     fn share_create(
         &self,
         uri: &Uri,
-        alias_id: &str,
+        alias_id: &AliasID,
         data: NewShareRequest,
-    ) -> error::Result<String>;
+    ) -> error::Result<ShareID>;
 
-    fn share_notify(&self, uri: &Uri, alias_id: &str, share_id: &str) -> error::Result<()>;
+    fn share_notify(&self, uri: &Uri, alias_id: &AliasID, share_id: &ShareID) -> error::Result<()>;
 
     fn file_create(
         &self,
         uri: &Uri,
-        alias_id: &str,
-        share_id: &str,
+        alias_id: &AliasID,
+        share_id: &ShareID,
         file: &file::Checked,
     ) -> error::Result<FileID>;
 
     fn file_patch(
         &self,
         uri: &Uri,
-        alias_id: &str,
-        share_id: &str,
+        alias_id: &AliasID,
+        share_id: &ShareID,
         chunk: &file::Chunk,
     ) -> error::Result<()>;
 }
diff --git a/src/sharry/mod.rs b/src/sharry/mod.rs
index a37d19c..8b53aca 100644
--- a/src/sharry/mod.rs
+++ b/src/sharry/mod.rs
@@ -1,5 +1,7 @@
 mod api;
 mod client;
 
-pub use api::{FileID, NewShareRequest, NewShareResponse, NotifyShareResponse, Uri};
+pub use api::{
+    AliasID, FileID, NewShareRequest, NewShareResponse, NotifyShareResponse, ShareID, Uri,
+};
 pub use client::Client;