Comproportionation or symproportionation is a chemical reaction where two reactants, each containing the same element but with a different oxidation number, will form a product in which the elements involved reach the same oxidation number. Potassium permanganate contains manganese with oxidation number of +7 and reacts with a manganese compound having oxidation number +2 to yield manganese(IV) oxide (manganese dioxide) with oxidation number +4, potassium hydroxide and water.
Secure Shell, or SSH, is a cryptographic (encrypted) network protocol to allow remote login and other network services to operate securely over an unsecured network. SSH provides a secure channel over an unsecured network in a client-server architecture, connecting an SSH client application with an SSH server.
Now all the details of ssh login attempts will be saved in your /var/log/auth.log file. If you have started using a different port, or if you think your server is well-enough hidden not to need much security, you should increase your logging level and examine your auth.log file every so often.