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diff --git a/markdown/Requirements.md b/markdown/Requirements.md new file mode 100644 index 0000000..434e4db --- /dev/null +++ b/markdown/Requirements.md @@ -0,0 +1,172 @@ +# HSM Requirements + +Requirements for the Cryptech Alpha System. Derived from Use Cases (see below). There are also utility, internal requirements (again, see below). + +## Capacity +### Per key storage requirements +In addition to the actual key data, each key requires + +- Key type – 4 bytes +- Key identifier – 4 bytes +- Key flags, e.g. exportable – 8 bytes + +This results a total 16 bytes overhead for each key. + +### Examples per algorithm +(For RSA, we might also want to include the primes p and q might also be included which requires additional storage.) + + +- RSA-8192 requires 1024 bytes secret key, 1024 bytes public key + 4 bytes exponent + 16 bytes overhead = 2068 bytes +- RSA-4096 requires 512 bytes secret key, 512 bytes public key + 4 bytes exponent + 16 bytes overhead = 1044 bytes +- RSA-2048 requires 256 bytes secret key, 256 bytes public key + 4 bytes exponent + 16 bytes overhead = 532 bytes +- EC P-256 requires 32 bytes secret key, 64 bytes public key + 16 bytes overhead = 112 bytes +- EC P-384 requires 48 bytes secret key, 96 bytes public key + 16 bytes overhead = 160 bytes +- Curve 25519 requires 32 bytes secret key, 32 bytes public key + 16 bytes overhead = 80 bytes + + + +## Use Cases +### DNSSEC +#### Number of keys + +- TLD (or provider using key sharing) requires ~ 100 key pairs +- 3 KSK per zone (previous, current, new) +- 3 ZSK per zone (previous, current, new) + +#### Possibly dual algorithms + +- A typical TLD operator usually has less than 10 TLDs +- Other DNS providers may use key sharing to limit number of keys required + +#### Algorithms + +- RSA-1024/SHA-256 +- RSA-2048/SHA-256 +- EC-P256/SHA-256 + +#### Performance +Each update to a zone requires 3-4 signatures (per algorithm) + +- Resign SOA (signed by ZSK) +- Resign updated RR (signed by ZSK) +- Resign NSEC/NSEC3 (signed by ZSK), may require multiple signatures + +Non-interactive latency (batch), dynamic updates may require faster signing + +### SAML +#### Number of keys +SAML federation operator requires max 10 key pairs (including space for roll) +#### Algorithms + +- RSA-2048/SHA-256 + +#### Performance + +- Non-interactive latency (batch) + - non-MDX: … +- Interactive latency + - MDX: … + + +### PKIX (including RPKI) +#### Number of keys + +- Typical Certification Authority ~ 10 key pairs + - CA key, OCSP, CRL per level in the CA + - Root CA is one level + - For subordinate CAs, perhaps 2-5 CAs in a HSM is reasonable? + +#### Algorithms + +- RSA-2048/SHA-256 +- RSA-4096/SHA-256 +- RSA-4096/SHA-512 ? +- EC-P256/SHA-256 + +#### Performance + +- Non-interactive latency + - Root CA: Less than 1 signature per day + - Issuing CA: One signature per issued certificate + - CRL: Less than 1 signature per hour +- Interactive latency + - OCSP: Multiple signatures per second + + +### Tor +Requirements according to (section 1): https://gitweb.torproject.org/torspec.git/plain/dir-spec.txt +#### Number of keys + +- 1 private key +- 10 public keys + +#### Algorithms + +- RSA-2048/SHA-1 ? +- RSA-2048/SHA-256 +- RSA-4096/SHA-256 ? +- RSA-4096/SHA-512 ? + +#### Performance + +- 2 signatures per hour +- 20 verification operations per hour +- 1 second max latency for RSA-2048 based verification + + +### Certificate Transparency (CT) +#### Number of keys +CT requires 1 key (ECDSA or RSA) per log +#### Algorithms + +- RSA-2048/SHA-256 +- RSA-4096/SHA-256 ? +- RSA-4096/SHA-512 ? +- EC-P256/SHA-256 + +#### Performance + +- A Certificate Transparency log uses one ECDSA or one RSA key to sign two separate documents: +- STH's might need to be signed once per hour +- SCT's might need to be signed once per second (*) + + +See RFC 6962, section 2.1.4 – https://tools.ietf.org/html/rfc6962 + + +## Internal Functional Requirements + +### Algorithms and functions + +- Key wrapping using AES-256 with SIV, http://tools.ietf.org/html/rfc5297 +- Internal Storage Master Key (ISMK) in battery backed RAM connected to FPGA + - Battery connection controlled by tamper mechanism + - Active erasure controlled by tamper mechanism +- 32-bit high quality random number generation + + +### PKCS11 + +The following PKCS11 mechanisms are required to fulfill the aforementioned use cases: + + +- RSA + - CKM_RSA_PKCS_KEY_PAIR_GEN + - CKM_RSA_PKCS + - CKM_RSA_X_509 ? + - CKM_SHA256_RSA_PKCS + - CKM_SHA512_RSA_PKCS ? +- ECDSA + - CKM_EC_KEY_PAIR_GEN + - CKM_ECDSA +- AES + - … TBD … +- Random + - … TBD … +- Key Wrapping + - … TBD … +- Hash + - CKM_SHA256 + - CKM_SHA512 (?) + + |