# Playfair cipher

> early block substitution cipher

**Wikidata**: [Q829915](https://www.wikidata.org/wiki/Q829915)  
**Wikipedia**: [English](https://en.wikipedia.org/wiki/Playfair_cipher)  
**Source**: https://4ort.xyz/entity/playfair-cipher


## References

1. Freebase Data Dumps. 2013