What was NIST’s reason to switch naming from MD… (Message Digest) to SHA… (Secure Hashing Algorithm)? When NIST introduced SHA-0 in 1993, they – for the first time – switched their naming convention from MD-n to SHA-n. Since both point to similar constructions (read: hashing algorithms with the same cryptographic goals), I am wondering why NIST chose to change the naming from „Message Digest“ to „Secure Hashing Algorithm“. A look around didn’t return useful information related to this. 

Was there a specific reason to change the existing naming convention? Does it in some way indicate that there was change in cryptographic goals (and if, which ones) or was it simply the result of a standardization decision, potentially based on terminological changes within NIST definitions? 

In case there’s an official statement explaining this change in naming convention, I’ld also appreciate a pointer to it for reference purposes.
When NIST introduced SHA-0 in 1993, they – for the first time – switched their naming convention from MD-n to SHA-n


Actually, MD-n was not NIST's naming conventions; it was RSA Security's (a private company) naming convention.  Before SHA (which was the original name; SHA-0 is retroactive terminology given to distinguish the original proposal from what was finally adopted: SHA-1), NIST didn't define any hash functions.