R2511-HP MSR Router Series Security Configuration Guide(V5)

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Managing public keys
To protect data confidentiality during transmission, the data sender uses an algorithm and a key to
encrypt the plain text data before sending the data out. The receiver uses the same algorithm with the
help of a key to decrypt the data, as shown in Figure 74.
Figure 74 Encryption an
d decryption
The keys that participate in the conversion between plain text and cipher text can be the same or different,
dividing the encryption and decryption algorithms into the following types:
• Symmetric key algorithm—The keys for encryption and decryption are the same.
• Asymmetric key algorithm—The keys for encryption and decryption are different. One is the public
key, and the other is the private key. The information encrypted with the public key can only be
decrypted with the corresponding private key, and vice versa. The private key is kept secret, and the
public key can be distributed widely. The private key cannot be practically derived from the public
key. Asymmetric key algorithms include RSA and DSA.
The asymmetric key algorithms can be used for the following purposes:
• To encrypt and decrypt data—Any public key receiver can use the public key to encrypt information,
but only the private key owner can decrypt the information. This mechanism ensures confidentiality.
Only RSA can be used for data encryption and decryption.
• To authenticate a sender—Also called "digital signature." The key owner uses the private key to
"sign" information to be sent, and the receiver decrypts the information with the sender's public key
to verify information authenticity. RSA and DSA can be used for digital signature.
Asymmetric key algorithms are widely used in various applications. For example, SSH, SSL, and PKI use
the algorithms for digital signature. For information about SSH, SSL, and PKI, see "Configuring SSH,"
"Configuring SSL," and "Configuring PKI."
FIPS compliance
Table 15 shows the support of devices for the FIPS mode that complies with NIST FIPS 140 -2 requirements.
Support for features, commands, and parameters might differ in FIPS mode and non-FIPS mode. For
more information about FIPS mode, see Security Configuration Guide.
Table 15 Hardware and FIPS mode compatibility matrix
Hardware FIPS mode
MSR900 No.
MSR93X No.
MSR20-1X No.