Symmetric (same key to crypt and decrypt)
- 3DES (Triple DES uses three individual keys with 56 bits each. The total key length adds up to 168 bits, but experts would argue that 112-bits in key strength is more like it)
- AES [Rijndael] (Although it is extremely efficient in 128-bit form, AES also uses keys of 192 and 256 bits for heavy duty encryption purposes)
Asymmetric (one unique private key, and a different public key to crypt and decrypt, remember Kleopatra sf) *Public key / Private key
- Diffie-Hellman (DH)
- RSA (RSA is a public-key encryption algorithm and the standard for encrypting data sent over the internet. It also happens to be one of the methods used in our PGP and GPG programs)
Hashes (validate data integrity, you get a finger print)
- SHA-1 (160bits – 512bits)
- MD5 (128bits)
An attachment to an electronic message used for security purposes. The most common use of a digital certificate is to verify that a user sending a message is who he or she claims to be, and to provide the receiver with the means to encode a reply.
An individual that wants to send an encrypted message applies for a digital certificate from a Certificate Authority (CA). The CA issues an encrypted digital certificate containing the applicant’s public key and a variety of other identification information. The CA makes its own public key readily available through print publicity or perhaps on the Internet.
The recipient of an encrypted message uses the CA’s public key to decode the digital certificate attached to the message, verifies it as issued by the CA and then obtains the sender’s public key and identification information held within the certificate. With this information, the recipient can send an encrypted reply.
The most widely used standard for digital certificates is X.509.
A digital certificate is an electronic “passport” that allows a person, computer or organization to exchange information securely over the Internet using the public key infrastructure (PKI).