diff --git a/include/psa/crypto_sizes.h b/include/psa/crypto_sizes.h
index 205bd0b..12bbf6e 100644
--- a/include/psa/crypto_sizes.h
+++ b/include/psa/crypto_sizes.h
@@ -140,7 +140,7 @@
  */
 #define PSA_AEAD_TAG_LENGTH(key_type, key_bits, alg)                        \
     (PSA_AEAD_NONCE_LENGTH(key_type, alg) ?                                 \
-     ((alg) & PSA_ALG_AEAD_TAG_LENGTH_MASK) >> PSA_AEAD_TAG_LENGTH_OFFSET : \
+     PSA_ALG_AEAD_GET_TAG_LENGTH(alg) :                                     \
      ((void) (key_bits), 0))
 
 /** The maximum tag size for all supported AEAD algorithms, in bytes.
@@ -271,7 +271,7 @@
  */
 #define PSA_AEAD_ENCRYPT_OUTPUT_SIZE(key_type, alg, plaintext_length) \
     (PSA_AEAD_NONCE_LENGTH(key_type, alg) ?                           \
-     (plaintext_length) + PSA_AEAD_TAG_LENGTH(key_type, 0, alg) :     \
+     (plaintext_length) + PSA_ALG_AEAD_GET_TAG_LENGTH(alg) :          \
      0)
 
 /** A sufficient output buffer size for psa_aead_encrypt(), for any of the
@@ -324,7 +324,7 @@
  */
 #define PSA_AEAD_DECRYPT_OUTPUT_SIZE(key_type, alg, ciphertext_length) \
     (PSA_AEAD_NONCE_LENGTH(key_type, alg) ?                            \
-     (ciphertext_length) - PSA_AEAD_TAG_LENGTH(key_type, 0, alg) :     \
+     (ciphertext_length) - PSA_ALG_AEAD_GET_TAG_LENGTH(alg) :          \
      0)
 
 /** A sufficient output buffer size for psa_aead_decrypt(), for any of the
@@ -375,14 +375,11 @@
  */
 #define PSA_AEAD_NONCE_LENGTH(key_type, alg) \
     (PSA_BLOCK_CIPHER_BLOCK_LENGTH(key_type) == 16 ? \
-          PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0) == \
-              PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CCM, 0) ? 13 : \
-          PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0) == \
-              PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_GCM, 0) ? 12 : \
+          PSA_ALG_AEAD_IS_BASE_EQUAL(alg, PSA_ALG_CCM) ? 13 : \
+          PSA_ALG_AEAD_IS_BASE_EQUAL(alg, PSA_ALG_GCM) ? 12 : \
           0 : \
      (key_type) == PSA_KEY_TYPE_CHACHA20 && \
-          PSA_ALG_AEAD_WITH_SHORTENED_TAG(alg, 0) == \
-              PSA_ALG_AEAD_WITH_SHORTENED_TAG(PSA_ALG_CHACHA20_POLY1305, 0) ? 12 : \
+          PSA_ALG_AEAD_IS_BASE_EQUAL(alg, PSA_ALG_CHACHA20_POLY1305) ? 12 : \
      0)
 
 /** The maximum default nonce size among all supported pairs of key types and
diff --git a/include/psa/crypto_values.h b/include/psa/crypto_values.h
index 5e865c9..de5a3c8 100644
--- a/include/psa/crypto_values.h
+++ b/include/psa/crypto_values.h
@@ -1175,6 +1175,20 @@
  * encoded in #PSA_ALG_AEAD_TAG_LENGTH_MASK. */
 #define PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG  ((psa_algorithm_t)0x00008000)
 
+/** Macro to test whether two AEAD algorithms correspond to the same base algorithm.
+ *
+ * \param aead_alg_1 An AEAD algorithm identifier.
+ * \param aead_alg_2 An AEAD algorithm identifier.
+ *
+ * \return           1 if the base both arguments correspond to the same base
+ *                   algorithm, 0 otherwise.
+ *                   Unspecified if \p aead_alg_1 or \p aead_alg_2 are not
+ *                   supported AEAD algorithms.
+ */
+#define PSA_ALG_AEAD_IS_BASE_EQUAL(aead_alg_1, aead_alg_2) \
+    (!(((aead_alg_1) ^ (aead_alg_2)) & \
+       ~(PSA_ALG_AEAD_TAG_LENGTH_MASK | PSA_ALG_AEAD_AT_LEAST_THIS_LENGTH_FLAG)))
+
 /** Macro to build a shortened AEAD algorithm.
  *
  * A shortened AEAD algorithm is similar to the corresponding AEAD