diff --git a/include/mbedtls/aes.h b/include/mbedtls/aes.h
index 1ddde82..fb97c7b 100644
--- a/include/mbedtls/aes.h
+++ b/include/mbedtls/aes.h
@@ -83,24 +83,24 @@
  *
  * \param ctx      AES context to be initialized
  * \param key      encryption key
- * \param keysize  must be 128, 192 or 256
+ * \param keybits  must be 128, 192 or 256
  *
  * \return         0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
  */
 int mbedtls_aes_setkey_enc( mbedtls_aes_context *ctx, const unsigned char *key,
-                    unsigned int keysize );
+                    unsigned int keybits );
 
 /**
  * \brief          AES key schedule (decryption)
  *
  * \param ctx      AES context to be initialized
  * \param key      decryption key
- * \param keysize  must be 128, 192 or 256
+ * \param keybits  must be 128, 192 or 256
  *
  * \return         0 if successful, or MBEDTLS_ERR_AES_INVALID_KEY_LENGTH
  */
 int mbedtls_aes_setkey_dec( mbedtls_aes_context *ctx, const unsigned char *key,
-                    unsigned int keysize );
+                    unsigned int keybits );
 
 /**
  * \brief          AES-ECB block encryption/decryption
diff --git a/include/mbedtls/asn1.h b/include/mbedtls/asn1.h
index bec24d1..675a8eb 100644
--- a/include/mbedtls/asn1.h
+++ b/include/mbedtls/asn1.h
@@ -119,7 +119,7 @@
 typedef struct mbedtls_asn1_buf
 {
     int tag;                /**< ASN1 type, e.g. MBEDTLS_ASN1_UTF8_STRING. */
-    size_t len;             /**< ASN1 length, e.g. in octets. */
+    size_t len;             /**< ASN1 length, in octets. */
     unsigned char *p;       /**< ASN1 data, e.g. in ASCII. */
 }
 mbedtls_asn1_buf;
@@ -129,7 +129,7 @@
  */
 typedef struct mbedtls_asn1_bitstring
 {
-    size_t len;                 /**< ASN1 length, e.g. in octets. */
+    size_t len;                 /**< ASN1 length, in octets. */
     unsigned char unused_bits;  /**< Number of unused bits at the end of the string */
     unsigned char *p;           /**< Raw ASN1 data for the bit string */
 }
diff --git a/include/mbedtls/blowfish.h b/include/mbedtls/blowfish.h
index d692058..74bbe26 100644
--- a/include/mbedtls/blowfish.h
+++ b/include/mbedtls/blowfish.h
@@ -80,12 +80,12 @@
  *
  * \param ctx      Blowfish context to be initialized
  * \param key      encryption key
- * \param keysize  must be between 32 and 448 bits
+ * \param keybits  must be between 32 and 448 bits
  *
  * \return         0 if successful, or MBEDTLS_ERR_BLOWFISH_INVALID_KEY_LENGTH
  */
 int mbedtls_blowfish_setkey( mbedtls_blowfish_context *ctx, const unsigned char *key,
-                     unsigned int keysize );
+                     unsigned int keybits );
 
 /**
  * \brief          Blowfish-ECB block encryption/decryption
diff --git a/include/mbedtls/camellia.h b/include/mbedtls/camellia.h
index c160341..37675d1 100644
--- a/include/mbedtls/camellia.h
+++ b/include/mbedtls/camellia.h
@@ -76,24 +76,24 @@
  *
  * \param ctx      CAMELLIA context to be initialized
  * \param key      encryption key
- * \param keysize  must be 128, 192 or 256
+ * \param keybits  must be 128, 192 or 256
  *
  * \return         0 if successful, or MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH
  */
 int mbedtls_camellia_setkey_enc( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keysize );
+                         unsigned int keybits );
 
 /**
  * \brief          CAMELLIA key schedule (decryption)
  *
  * \param ctx      CAMELLIA context to be initialized
  * \param key      decryption key
- * \param keysize  must be 128, 192 or 256
+ * \param keybits  must be 128, 192 or 256
  *
  * \return         0 if successful, or MBEDTLS_ERR_CAMELLIA_INVALID_KEY_LENGTH
  */
 int mbedtls_camellia_setkey_dec( mbedtls_camellia_context *ctx, const unsigned char *key,
-                         unsigned int keysize );
+                         unsigned int keybits );
 
 /**
  * \brief          CAMELLIA-ECB block encryption/decryption
diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h
index 894794d..a1dba4f 100644
--- a/include/mbedtls/ccm.h
+++ b/include/mbedtls/ccm.h
@@ -56,14 +56,14 @@
  * \param ctx       CCM context to be initialized
  * \param cipher    cipher to use (a 128-bit block cipher)
  * \param key       encryption key
- * \param keysize   key size in bits (must be acceptable by the cipher)
+ * \param keybits   key size in bits (must be acceptable by the cipher)
  *
  * \return          0 if successful, or a cipher specific error code
  */
 int mbedtls_ccm_setkey( mbedtls_ccm_context *ctx,
                         mbedtls_cipher_id_t cipher,
                         const unsigned char *key,
-                        unsigned int keysize );
+                        unsigned int keybits );
 
 /**
  * \brief           Free a CCM context and underlying cipher sub-context
diff --git a/include/mbedtls/cipher.h b/include/mbedtls/cipher.h
index 58c974b..46b82ca 100644
--- a/include/mbedtls/cipher.h
+++ b/include/mbedtls/cipher.h
@@ -282,14 +282,14 @@
  *
  * \param cipher_id     Id of the cipher to search for
  *                      (e.g. MBEDTLS_CIPHER_ID_AES)
- * \param key_length    Length of the key in bits
+ * \param key_bitlen    Length of the key in bits
  * \param mode          Cipher mode (e.g. MBEDTLS_MODE_CBC)
  *
  * \return              the cipher information structure associated with the
  *                      given cipher_type, or NULL if not found.
  */
 const mbedtls_cipher_info_t *mbedtls_cipher_info_from_values( const mbedtls_cipher_id_t cipher_id,
-                                              int key_length,
+                                              int key_bitlen,
                                               const mbedtls_cipher_mode_t mode );
 
 /**
@@ -447,7 +447,7 @@
  *                      initialised using cipher_context_from_type or
  *                      cipher_context_from_string.
  * \param key           The key to use.
- * \param key_length    key length to use, in bits.
+ * \param key_bitlen    key length to use, in bits.
  * \param operation     Operation that the key will be used for, either
  *                      MBEDTLS_ENCRYPT or MBEDTLS_DECRYPT.
  *
@@ -456,7 +456,7 @@
  *                      error code.
  */
 int mbedtls_cipher_setkey( mbedtls_cipher_context_t *ctx, const unsigned char *key,
-                   int key_length, const mbedtls_operation_t operation );
+                   int key_bitlen, const mbedtls_operation_t operation );
 
 #if defined(MBEDTLS_CIPHER_MODE_WITH_PADDING)
 /**
diff --git a/include/mbedtls/gcm.h b/include/mbedtls/gcm.h
index c2f6d68..c6e9d26 100644
--- a/include/mbedtls/gcm.h
+++ b/include/mbedtls/gcm.h
@@ -69,14 +69,14 @@
  * \param ctx       GCM context to be initialized
  * \param cipher    cipher to use (a 128-bit block cipher)
  * \param key       encryption key
- * \param keysize   must be 128, 192 or 256
+ * \param keybits   must be 128, 192 or 256
  *
  * \return          0 if successful, or a cipher specific error code
  */
 int mbedtls_gcm_setkey( mbedtls_gcm_context *ctx,
                         mbedtls_cipher_id_t cipher,
                         const unsigned char *key,
-                        unsigned int keysize );
+                        unsigned int keybits );
 
 /**
  * \brief           GCM buffer encryption/decryption using a block cipher
diff --git a/include/mbedtls/md.h b/include/mbedtls/md.h
index cb3e058..8e57025 100644
--- a/include/mbedtls/md.h
+++ b/include/mbedtls/md.h
@@ -172,7 +172,7 @@
  *
  * \param md_info   message digest info
  *
- * \return          size of the message digest output.
+ * \return          size of the message digest output in bytes.
  */
 unsigned char mbedtls_md_get_size( const mbedtls_md_info_t *md_info );
 
@@ -269,7 +269,7 @@
  *
  * \param ctx       HMAC context
  * \param key       HMAC secret key
- * \param keylen    length of the HMAC key
+ * \param keylen    length of the HMAC key in bytes
  *
  * \returns         0 on success, MBEDTLS_ERR_MD_BAD_INPUT_DATA if parameter
  *                  verification fails.
@@ -323,7 +323,7 @@
  *
  * \param md_info  message digest info
  * \param key      HMAC secret key
- * \param keylen   length of the HMAC key
+ * \param keylen   length of the HMAC key in bytes
  * \param input    buffer holding the  data
  * \param ilen     length of the input data
  * \param output   Generic HMAC-result
diff --git a/include/mbedtls/md_internal.h b/include/mbedtls/md_internal.h
index 8cc8c5b..fe0feb3 100644
--- a/include/mbedtls/md_internal.h
+++ b/include/mbedtls/md_internal.h
@@ -52,10 +52,10 @@
     /** Name of the message digest */
     const char * name;
 
-    /** Output length of the digest function */
+    /** Output length of the digest function in bytes */
     int size;
 
-    /** Block length of the digest function */
+    /** Block length of the digest function in bytes */
     int block_size;
 
     /** Digest initialisation function */