ECE Prof. John A. Copeland fax Office: GCATT Bldg 579 or call for office visit, or call Kathy Cheek, Chapter 4b - X.509 Authentication

X.509 Authentication Service An International Telecommunications Union (ITU) recommendation (versus “standard”) for allowing computer host or users to securely identify themselves over a network. An X.509 certificate purchased from a “Certificate Authority” (trusted third party) allows a merchant to give you his public key in a way that your Browser can generate a session key for a transaction, and securely send that to the merchant for use during the transaction (padlock icon on screen closes to indicate transmissions are encrypted). Once a session key is established, no one can “high jack” the session (for example, after your enter your credit card information, an intruder can not change the order and delivery address). User only needs a Browser that can encrypt/decrypt with the appropriate algorithm, and generate session keys from truly random numbers. Merchant’s Certificate is available to the public, only the secret key must be protected. Certificates can be cancelled if secret key is compromised.

Certificate Authority generates the “signature” that is added to raw “Certificate” MIC Hash Raw “Certificate” has user name, public key, expiration date,... Raw Cert. Signed Cert. 3 Generate hash code of Raw Certificate Encrypt hash code with CA’s private key to form CA’s signature Signed Certificate Recipient can verify signature using CA’s public key.

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//investing.schwab.com/trading/ has the following structure: Form 1: Action URL: 1 Encoding: application/x-www-form-urlencoded (default) Method: Post Image: 5

This Certificate belongs to: investing.schwab.com trading subnet a 1199 Charles Schwab & Co., Inc. Phoenix, Arizona, US This Certificate was issued by: Secure Server Certification Authority RSA Data Security, Inc. US Serial Number: 6B:68:2F:3B:FD:8A:46:73:04:33:10:8A:32:1E:47:5B This Certificate is valid from Wed Nov 03, 1999 to Thu Nov 02, 2000 Certificate Fingerprint: 4B:80:C6:C5:2D:63:14:E7:6F:50:BD:16:39:3C:96:FD 6

Are you sure that you want to delete this Site Certificate? This Certificate belongs to: endor.mcom.com Netscape Communications Corp. US This Certificate was issued by: rootca.netscape.com Information Systems Netscape Communications Corporation US Serial Number: 01:77 This Certificate is valid from Thu May 15, 1997 to Tue Nov 11, 1997 Certificate Fingerprint: 06:BF:60:88:D9:E7:59:BF:3A:35:74:33:28:8E:26:F6 7

X.509 Chain of Authentication CA > = CA {A’s id and information} X > = certificate of A “signed” by X To authenticate X >, you must get the public key of X from a trusted source, such as Z - your own CA. ( Z >) Z in turn may have to get X’s certificate from a higher level CA. Ultimately there must be an “Authentication Tree” of CA’s so that a user can work up the tree (from Z) and back down to the issuer of the certificate in question, X. 8

X.509 Chain of Authentication 9

Examples: "A" = decimal 65 = , "z" =

Making a DES Key from a Password or Phrase password, n 7-bit ASCII characters (little endian - least significant bit first) flattened bit stream (7 x n bits) fanfold into 56 bits bitwise XOR 64-bit key Every eighth bit is a parity bit 11

Programs Available from hextext.c - allows you to view files in both hex and ascii formats. char_count.c - shows the number of different characters in a file, computes the character entropy. To use, you must first compile them. On a UNIX or LINUX: gcc hextext.c -o hextext (the executable file is “hextext”)./hextext for help./hextext filename 3000file and max. bytes./hextext filename 3000 | less see one screen at a time gcc char_count.c -lm -o char_count (note the “-lm” for math library)./char_count filename If “gcc” is not available, try “cc”. “less” is better than “more” (use “^u” to back up, “space” for next page). 12

Maximum Lines (p_limit) value: 30 Input File is s100.raw Byte No. HEX VALUES TEXT : d4c3 b2a : d... 20: e ead e e :.....DH8....N...N... 40: da3 : : f11 16fc f : c 90c7 061a :.B...5., : : : e fd a400 : u......DH8!...r : f00 : P.. 160: 308c acf 4000 fc11 d : 180: f a8a 061a :.X0/.5....z : : : c00c a1ce 0010 : edu Lines: 30, hextext.c by John Copeland 12/5/99 Output from ‘hextext’ 13

$./char_count char_count.c char_count vers File is char_count.c No. Char.s to EOF = 7396, No. Lines = 183 Occurrence of Single Characters 0 | ^P- 0 | | | P- 12 | `- 0 | p- 154 ^A- 0 | ^Q- 0 | !- 1 | | A- 16 | Q- 0 | a- 202 | q- 0 ^B- 0 | ^R- 0 | "- 75 | | B- 5 | R- 14 | b- 48 | r- 316 ^C- 0 | ^S- 0 | #- 9 | | C- 16 | S- 14 | c- 262 | s- 243 ^D- 0 | ^T- 0 | $- 0 | | D- 8 | T- 25 | d- 95 | t- 263 ^E- 0 | ^U- 0 | %- 32 | | E- 27 | U- 8 | e- 296 | u- 108 ^F- 0 | ^V- 0 | &- 1 | | F- 13 | V- 0 | f- 154 | v- 45 ^G- 0 | ^W- 0 | '- 18 | | G- 0 | W- 0 | g- 78 | w- 8 ^H- 0 | ^X- 0 | (- 116 | | H- 0 | X- 0 | h- 100 | x- 31 ^I- 18 | ^Y- 0 | )- 116 | 9- 4 | I- 27 | Y- 2 | i- 338 | y- 64 ^J- 247 | ^Z- 0 | *- 232 | :- 5 | J- 0 | Z- 0 | j- 13 | z- 4 ^K- 0 | ^[- 0 | | ;- 193 | K- 1 | [- 104 | k- 6 | {- 24 ^L- 0 | ^\- 0 |,- 109 | <- 35 | L- 22 | \- 29 | l- 152 | |- 4 ^M- 0 | ^]- 0 | | =- 121 | M- 5 | ]- 102 | m- 123 | }- 24 ^N- 0 | ^^- 0 |.- 51 | >- 31 | N- 29 | ^- 4 | n- 342 | ~- 0 ^O- 0 | ^_- 0 | /- 255 | ?- 0 | O- 17 | _- 27 | o- 213 | - 0 Occurrence of Single Characters - Sorted | "- 75 | F- 13 | `- 0 | | A0- 0 | C0- 0 | E0- 0 Output from ‘char_count’ 14

Occurrence of Single Characters - Sorted | "- 75 | F- 13 | `- 0 | | A0- 0 | C0- 0 | E0- 0 n- 342 | | P- 12 | Q- 0 | | A1- 0 | C1- 0 | E1- 0 i- 338 | y- 64 | | ^B- 0 | | A2- 0 | C2- 0 | E2- 0 r- 316 |.- 51 | #- 9 | ^C- 0 | | A3- 0 | C3- 0 | E3- 0 e- 296 | b- 48 | D- 8 | $- 0 | | A4- 0 | C4- 0 | E4- 0 t- 263 | v- 45 | w- 8 | ^E- 0 | | A5- 0 | C5- 0 | E5- 0 c- 262 | | U- 8 | ^F- 0 | | A6- 0 | C6- 0 | E6- 0 /- 255 | <- 35 | k- 6 | G- 0 | | A7- 0 | C7- 0 | E7- 0 ^J- 247 | %- 32 | :- 5 | H- 0 | | A8- 0 | C8- 0 | E8- 0 s- 243 | x- 31 | B- 5 | ^A- 0 | | A9- 0 | C9- 0 | E9- 0 *- 232 | >- 31 | M- 5 | J- 0 | 8A- 0 | AA- 0 | CA- 0 | EA- 0 o- 213 | | |- 4 | ^K- 0 | 8B- 0 | AB- 0 | CB- 0 | EB- 0 a- 202 | \- 29 | ^- 4 | ^L- 0 | 8C- 0 | AC- 0 | CC- 0 | EC- 0 ;- 193 | N- 29 | z- 4 | ^M- 0 | 8D- 0 | AD- 0 | CD- 0 | ED- 0 p- 154 | _- 27 | 9- 4 | ^N- 0 | 8E- 0 | AE- 0 | CE- 0 | EE- 0 f- 154 | I- 27 | Y- 2 | ^O- 0 | 8F- 0 | AF- 0 | CF- 0 | EF- 0 l- 152 | E | ^P- 0 | | B0- 0 | D0- 0 | F0- 0 m- 123 | | &- 1 | q- 0 | | B1- 0 | D1- 0 | F1- 0 =- 121 | T- 25 | K- 1 | ^R- 0 | | B2- 0 | D2- 0 | F2- 0 (- 116 | {- 24 | !- 1 | ^S- 0 | | B3- 0 | D3- 0 | F3- 0 )- 116 | }- 24 | ^H- 0 | ^T- 0 | | B4- 0 | D4- 0 | F4- 0,- 109 | L- 22 | 0 | ^U- 0 | | B5- 0 | D5- 0 | F5- 0 u- 108 | '- 18 | ^V- 0 | V- 0 | | B6- 0 | D6- 0 | F | ^I- 18 | ^G- 0 | W- 0 | | B7- 0 | D7- 0 | F7- 0 [- 104 | | ^X- 0 | X- 0 | | B8- 0 | D8- 0 | F8- 0 ]- 102 | O- 17 | ?- 0 | ^Y- 0 | | B9- 0 | D9- 0 | F9- 0 h- 100 | | ^Z- 0 | Z- 0 | 9A- 0 | BA- 0 | DA- 0 | FA | C- 16 | ^W- 0 | ^[- 0 | 9B- 0 | BB- 0 | DB- 0 | FB- 0 d- 95 | A- 16 | ^D- 0 | ^\- 0 | 9C- 0 | BC- 0 | DC- 0 | FC- 0 g- 78 | R- 14 | ^Q- 0 | ^]- 0 | 9D- 0 | BD- 0 | DD- 0 | FD | S- 14 | ^^- 0 | ~- 0 | 9E- 0 | BE- 0 | DE- 0 | FE | j- 13 | ^_- 0 | bs- 0 | 9F- 0 | BF- 0 | DF- 0 | FF- 0 Entropy is 4.5 bits/byte. Maximum character-wise compression = 56.5 % No. Char.s > 127 (not ASCII text) = 0, 0 % 15