Someone can mine Digibyte with any of the five algorithms.
Sha256 (ASIC friendly)
Scrypt (ASIC friendly)
Groestl (GPU friendly)
Skein (GPU friendly)
Qubit (CPU friendly)
Each algorithm is assigned the 20% of the new blocks mining. The block size is doubled every two years, to scale the netwotk speed of transactions.
Year 2016: 280 Transactions Per Second
Year 2017: 560 Transactions Per Second
Year 2019: 1,120 Transactions Per Second
Year 2021: 2,240 Transactions Per Second
Year 2035: 280,000+ Transactions Per Second
Segwit has been already released.
References:
https://tsakf.quora.com/Digibyte-cryptocurrency