Concat combine several arrays into single one, resulting slice = A1 | A2 | A3 | ..

Dump produces printable debug representation of byte array as string.

Random generates byte array with random data of byteCount length.

Slice is splitting input byte array into slice of subarrays.

UInt32ToBytes unwrap uint32 value to byte array of length 4 using big endian.

UInt64ToBytes unwrap uint64 value to byte array of length 8 using big endian.

Unwrap same thing as Contact, just different interface, combines several array into single one.

Xor is doing byte by byte exclusive or of 2 byte arrays.