Use a faster hash function

[charliermarsh]

We probably don't need to be using something that's cryptographically secure (i.e., SHA-1). Instead, we could opt for a faster hash function (like Murmur) or use a checksum (like Adler-32 or CRC32).

For example, React uses Adler-32 to verify that server-generated markup matches client-generated markup (for server-side rendering).