Fast Software Encryption, often abbreviated FSE, is a workshop for cryptography research, focused on symmetric-key cryptography with an emphasis on fast, practical techniques, as opposed to theory. Though "encryption" is part of the conference title, it is not limited to encryption research; research on other symmetric techniques such as message authentication codes and hash functions is often presented there.
FSE has been an IACR workshop since 2002, though the first FSE workshop was held in 1993. FSE is held annually in various locations worldwide, mostly in Europe. The dates of the workshop have varied over the years, but recently, it has been held in February.