openpgp - algoritmos de hash, encriptación simétrica (cifrado), encriptación asimétrica (de llave pública) y compresión

openpgp-message-format.rst

References

• https://www.rfc-editor.org/rfc/rfc4880#section-9.4

Public-Key Algorithms

ID	Algorithm
1	RSA (Encrypt or Sign) [HAC]
2	RSA Encrypt-Only [HAC]
3	RSA Sign-Only [HAC]
16	Elgamal (Encrypt-Only) [ELGAMAL] [HAC]
17	DSA (Digital Signature Algorithm) [FIPS186] [HAC]
18	Reserved for Elliptic Curve
19	Reserved for ECDSA
20	Reserved (formerly Elgamal Encrypt or Sign)
21	Reserved for Diffie-Hellman (X9.42, as defined for IETF-S/MIME)
100 to 110	Private/Experimental algorithm

Implementations MUST implement DSA for signatures, and Elgamal for encryption.
Implementations SHOULD implement RSA keys (1).
RSA Encrypt-Only (2) and RSA Sign-Only are deprecated and SHOULD NOT be generated, but may be interpreted.

See Section 13.5.  See Section 13.8 for notes on Elliptic Curve (18), ECDSA (19), Elgamal Encrypt or Sign (20), and X9.42 (21).  Implementations MAY implement any other algorithm.

Symmetric-Key Algorithms

ID	Algorithm
0	Plaintext or unencrypted data
1	IDEA [IDEA]
2	TripleDES (DES-EDE, [SCHNEIER] [HAC] - 168 bit key derived from 192)
3	CAST5 (128 bit key, as per [RFC2144])
4	Blowfish (128 bit key, 16 rounds) [BLOWFISH]
5	Reserved
6	Reserved
7	AES with 128-bit key [AES]
8	AES with 192-bit key
9	AES with 256-bit key
10	Twofish with 256-bit key [TWOFISH]
100 to 110	Private/Experimental algorithm

Implementations MUST implement TripleDES.  Implementations SHOULD implement AES-128 and CAST5.
Implementations that interoperate with PGP 2.6 or earlier need to support IDEA, as that is the only
symmetric cipher those versions use.  Implementations MAY implement any other algorithm.

Compression Algorithms

ID	Algorithm
0	Uncompressed
1	ZIP [RFC1951]
2	ZLIB [RFC1950]
3	BZip2 [BZ2]
100 to 110	Private/Experimental algorithm

Implementations MUST implement uncompressed data.  Implementations SHOULD implement ZIP.
Implementations MAY implement any other algorithm.

Hash Algorithms

ID	Algorithm	Text Name
1	MD5 [HAC]	"MD5"
2	SHA-1 [FIPS180]	"SHA1"
3	RIPE-MD/160 [HAC]	"RIPEMD160"
4	Reserved
5	Reserved
6	Reserved
7	Reserved
8	SHA256 [FIPS180]	"SHA256"
9	SHA384 [FIPS180]	"SHA384"
10	SHA512 [FIPS180]	"SHA512"
11	SHA224 [FIPS180]	"SHA224"
100 to 110	Private/Experimental algorithm

Implementations MUST implement SHA-1.
Implementations MAY implement other algorithms.
MD5 is deprecated.