Generating a universally unique identifier (UUID) can be very useful for a variety of tasks where you need a unique way to identify something. While a UUID is not technically guaranteed to be unique, the identifier space is so large (128-bit) that it can be treated as unique for most purposes.
It is simple to generate a UUID string in MATLAB by using its built in Java Virtual Machine:
uuid = char(java.util.UUID.randomUUID);
The function java.util.UUID.randomUUID() will return an object of type java.util.UUID, but this can be typecasted into a MATLAB string through the char() function. Simple!