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SSH
,→Public Key Cryptography
To use public key cryptography:
# One key is designated as the "public key" and one is designated as the "private key".
#* The public key is distributed to all of the parties with whom you will be communicating. In fact, it can be communicated to anyone in the world.
#* The private key is ''never'' shared with anyone.
# Messages encrypted with your private key can only be decrypted with your public key, proving that the message came from you (authentication)
# The algorithms used in public-key cryptography are very slow. Therefore, it's common to use public key cryptography to exchange a key for a faster, symmetrical cypher, and then use that cypher for the actual data stream.
# ''Signing'' a message means authenticating it by taking a checksum (hash) of the message and encrypting that. This is faster than encrypting the entire message.
# Public key cryptography is very susceptible to the manipulation of public keys by an attacker interposed between the two parties at the time that the public keys are shared(e.g., when someone is downloading your public key from your website).# Public key cryptography is susceptible to theft of the private key(e.g., hacking your system, or stealing your laptop). The private key is therefore often protected with a passphrase.
== Using Public Keys with SSH ==