diff --git a/README.md b/README.md
index fbf6d31..c110e31 100644
--- a/README.md
+++ b/README.md
@@ -292,7 +292,7 @@ $ ./neofs-authmate issue-secret --wallet wallet.json \
 
 Enter password for wallet.json > 
 {
-  "access_key_id": "5g933dyLEkXbbAspouhPPTiyLZRg4axBW1axSPD87eVT_AiXsH4AjYy1iTJ4C1WExzjBrSobJsQFWEyKLREe5sQYM",
+  "access_key_id": "5g933dyLEkXbbAspouhPPTiyLZRg4axBW1axSPD87eVT0AiXsH4AjYy1iTJ4C1WExzjBrSobJsQFWEyKLREe5sQYM",
   "secret_access_key": "438bbd8243060e1e1c9dd4821756914a6e872ce29bf203b68f81b140ac91231c",
   "owner_private_key": "274fdd6e71fc6a6b8fe77bec500254115d66d6d17347d7db0880d2eb80afc72a"
 }
@@ -301,6 +301,9 @@ Enter password for wallet.json >
 Access key ID and secret access key are AWS credentials that you can use with
 any S3 client.
 
+Access key ID consists of Base58 encoded containerID(cid) and objectID(oid) stored on the NeoFS network and containing 
+the secret. Format of access_key_id: `%cid0%oid`, where 0(zero) is a delimiter.
+
 #### Obtainment of a secret access key
 
 You can get a secret access key associated with access key ID by obtaining a
@@ -312,7 +315,7 @@ and other (for `gate-wallet.json`) interactively:
   ./neofs-authmate obtain-secret --wallet wallet.json \
  --peer 192.168.130.71:8080 \
  --gate-wallet gate-wallet.json \
- --access-key-id 5g933dyLEkXbbAspouhPPTiyLZRg4axBW1axSPD87eVT_AiXsH4AjYy1iTJ4C1WExzjBrSobJsQFWEyKLREe5sQYM
+ --access-key-id 5g933dyLEkXbbAspouhPPTiyLZRg4axBW1axSPD87eVT0AiXsH4AjYy1iTJ4C1WExzjBrSobJsQFWEyKLREe5sQYM
 
 Enter password for gate-wallet.json >
 {
@@ -336,7 +339,7 @@ $ aws configure
 after you enter this command, the AWS CLI will prompt you for four pieces of information, like in this example
 (replace with your own values):
 ```
-AWS Access Key ID [None]: 5g933dyLEkXbbAspouhPPTiyLZRg4axBW1axSPD87eVT_AiXsH4AjYy1iTJ4C1WExzjBrSobJsQFWEyKLREe5sQYM
+AWS Access Key ID [None]: 5g933dyLEkXbbAspouhPPTiyLZRg4axBW1axSPD87eVT0AiXsH4AjYy1iTJ4C1WExzjBrSobJsQFWEyKLREe5sQYM
 AWS Secret Access Key [None]: 438bbd8243060e1e1c9dd4821756914a6e872ce29bf203b68f81b140ac91231c
 Default region name [None]: ru 
 Default output format [none]: json 
diff --git a/api/auth/center.go b/api/auth/center.go
index f909951..3dccb29 100644
--- a/api/auth/center.go
+++ b/api/auth/center.go
@@ -20,7 +20,8 @@ import (
 	"go.uber.org/zap"
 )
 
-var authorizationFieldRegexp = regexp.MustCompile(`AWS4-HMAC-SHA256 Credential=(?P<access_key_id_cid>[^/]+)_(?P<access_key_id_oid>[^/]+)/(?P<date>[^/]+)/(?P<region>[^/]*)/(?P<service>[^/]+)/aws4_request,\s*SignedHeaders=(?P<signed_header_fields>.+),\s*Signature=(?P<v4_signature>.+)`)
+// authorizationFieldRegexp -- is regexp for credentials with Base58 encoded cid and oid and '0' (zero) as delimiter.
+var authorizationFieldRegexp = regexp.MustCompile(`AWS4-HMAC-SHA256 Credential=(?P<access_key_id_cid>[^/]+)0(?P<access_key_id_oid>[^/]+)/(?P<date>[^/]+)/(?P<region>[^/]*)/(?P<service>[^/]+)/aws4_request,\s*SignedHeaders=(?P<signed_header_fields>.+),\s*Signature=(?P<v4_signature>.+)`)
 
 type (
 	// Center is a user authentication interface.
@@ -89,7 +90,7 @@ func (c *center) Authenticate(r *http.Request) (*accessbox.GateData, error) {
 		return nil, fmt.Errorf("failed to parse x-amz-date header field: %w", err)
 	}
 
-	accessKeyID := fmt.Sprintf("%s_%s", sms1["access_key_id_cid"], sms1["access_key_id_oid"])
+	accessKeyID := fmt.Sprintf("%s0%s", sms1["access_key_id_cid"], sms1["access_key_id_oid"])
 	accessKeyAddress := fmt.Sprintf("%s/%s", sms1["access_key_id_cid"], sms1["access_key_id_oid"])
 
 	address := object.NewAddress()
diff --git a/authmate/authmate.go b/authmate/authmate.go
index 58ab058..510caac 100644
--- a/authmate/authmate.go
+++ b/authmate/authmate.go
@@ -179,7 +179,7 @@ func (a *Agent) IssueSecret(ctx context.Context, w io.Writer, options *IssueSecr
 		return fmt.Errorf("failed to put bearer token: %w", err)
 	}
 
-	accessKeyID := address.ContainerID().String() + "_" + address.ObjectID().String()
+	accessKeyID := address.ContainerID().String() + "0" + address.ObjectID().String()
 
 	ir := &issuingResult{
 		AccessKeyID:     accessKeyID,