The evolving storage encryption market Alexander (S andy) S tewart S un M icros ys tems 1 S toragetek Drive, Louis ville, CO 80028 P hone:+1-303-673-2775 FAX: +1-303-661-5743 E-mail: alexander.s tewart@ s un.com Pres ented at the THIC Meeting at the National Center for Atmos pheric Res earch, 1850 Table Mes a Drive, Boulder CO 80305-5602 Augus t 21-22, 2007
Ciphers, Keys and Confusion A cipher is an algorithm for performing encryption (and the reverse, decryption) a series of welldefined steps that can be followed as a procedure. Symmetric Cryptography - a.k.a Secret Key Cryptography Same key used to encrypt and decrypt messages Problem is how to share key Asymmetric Cryptography - a.k.a Public Key Cryptography Different, mathematically linked keys for encryption and decryption Problem is process is computationally intensive
Symmetric Key Cryptography rot13 Algorithm is to rotate alphabet by n, Key n = 13 get well soon = trg jryy fbba Brute force attack requires <25 iterations Trivial to decipher using word structure Crytpoquip One letter substituted for another, key is definition of substitution get well soon = axo dxpp ywwr Brute force attack requires 4x 1026 iterations Easy to decipher using word structure AES (Advanced Encryption Standard) Message hashed using long key get well soon = dfcd3454bbea7 Brute force attack requires 3.67x1060 iterations when 256-bit key used No known alternative to brute force attack
Symmetric Key Cryptography Key Sharing Algorithm must be shared not an issue Key must be securely shared Independent secure communication Face-to-face whispered conversation Physically secured code-book Nested encrypted communication Hybrid approach using Public Keys to protect key transmissions
Key Protection = Volatile Memory = Non-volatile Memory Raw Key Values from CD or MARS Card Communications Key (Wrap Key(Media Key Split Key)) Media Key Split Key Wrap Key Communications Key Wrap Key (Media Key Split Key) Communications Key Media Key Split Key Wrap Key Communications Key
Asymmetric Key Cryptography History First invented (secretly) in early 1970 s by Ellis, Cocks and Williamson of UK GCHQ First published disclosure 1976 by Dr. Whit Diffie (Sun Fellow) and Martin Hellman Examples Diffie-Hellman key exchange RSA (Rivest, Shamir, Adleman) Elliptic Curve ElGamal
Asymmetric Key Cryptography How does it work Pairs of mathematically linked key values are created Public Key and Private Key The Public key may be widely distributed The public key is used by anyone wishing to send you a secure message Your Private key must be kept secret You use your private key to decrypt any secure message sent to you A message encrypted using your public key can only be decrypted using your private key Many people can send you messages encrypted using your public key but cannot read messages from other people encrypted using that public key
Asymmetric Key Cryptography Key Pairs The paired values are linked mathematically but it is not practicable to derive one from the other RSA Two large prime numbers form the key pairs The mathematical linkage is the exponentiation modulo of the product of these numbers Elliptic curve The two key pairs are the x/y coordinates of a defined elliptic curve
Example Drawing Wikipedia
Man-in-the-middle attack Alice s public key Message encrypted with Alice s public key Alice Alice s public key Substitute public key from Eric s key pair Eric Bob Eric s public key Decrypt, read or Message encrypted tamper, re-encrypt Message encrypted with Alice s public key with Eric s public key
Certificates and Certificate Authorities A Certificate binds a public key to a particular entity X.509 uses designated a set of Certificate Authorities who issue certificates PGP (Pretty Good Privacy) establishes a web of trust model where anyone can issue a certificate The structure of a user s X.509 v3 digital certificate is as follows: Certificate Version Serial Number Algorithm ID Issuer Validity Not Before Not After Subject Subject Public Key Info Public Key Algorithm Subject Public Key Issuer Unique Identifier (Optional) Subject Unique Identifier (Optional) Extensions (Optional) Certificate Signature Algorithm Certificate Signature The Certificate Authority has their own X.509 certificate that is used to validate the user s certificate Wikipedia
Asymmetric vs. Symmetric Comparison Asymmetric keys solve the problem of secure key communication Asymmetric key algorithms are much more computationally intensive Asymmetric key encryption requires significantly longer keys to achieve the same level of security as symmetric encryption
Optimum uses of Asymmetric Keys Secure transmission of short messages Credit card transactions using SSL/TLS protocols Digital Signature Proves that message comes from a trustable source Provide source with your public key Source hashes long message and attaches an encrypted (using your public key) version of the hash to the message On receipt, perform a separate hash of the message and compare it to the decrypted received hash Hybrid implementation with symmetric cryptography Plays to the strengths of both technologies Use Asymmetric Cryptography to securely share Symmetric Keys
Where do we go from here? Bulk encryption for Disk and Tape products is well under control Key Management is the issue Vendor specific systems exist IBM tailored to an IBM environment Sun independent of environment Backup Application Vendors are slow to engage Diligent efforts ongoing to define a compatible Key Management Protocol
Alphabet Soup NIST National Institute of Science and Technology FIPS Federal Information Processing Standard IEEE 1619 IEEE Encryption Working Groups 1619.1 1619.2 1619.3 TCG Trusted Computing Group T10/T11 SCSI Protocols
Evolving Products
Who is buying encryption Sun/STK Customers Upgrade for Encryption: Large Grocery Chain in Northern CA Large Office Supply Retailer Information Management Services Company Large Power (including Nuclear) Company Large Consumer Financial Services Company Major Finance House, Japan National Bank, Turkey National Bank, Poland etc.