Username Part - Basic Auth Is Just Encoding

The text before the colon is the username.

highlighted = computed this step

The colon splits the credential

The text before the colon becomes the username row.

\text{before colon}=\text{alice}

The username row is recomputed from the decoded credential bytes.

\text{username checked}

Anyone holding the header text can base-sixty-four decode the token in this toy example.

\text{decoded, not decrypted}

The username is just the first part of the decoded Basic credential.

\text{username split checked}