RFC 1186
MD4 Message Digest Algorithm
RFC 1186 · Part 1 of 3 🎀
Okay bestie, this one is the MD4 Message Digest Algorithm 🔥 The title block says it's RFC 1186, written by R. Rivest at the MIT Laboratory for Computer Science in the Network Working Group, and it's dated October 1990 💖 It's informational, not a standard 🙈 The header doesn't list anything it obsoletes or updates, so it's giving standalone energy 💅
Status of this Memo 📜
Okay so the memo is the spec for the MD4 Digest Algorithm 🧚 If you're gonna implement MD4, the author suggests you do it this way ✨ It's for informational use only and does not count as a standard. Distribution is unlimited, so share it with everyone 🌸
Table of Contents
1. Abstract .................................................... 1
2. Terminology and Notation .................................... 2
3. MD4 Algorithm Description ................................... 2
4. Extensions .................................................. 6
5. Summary ..................................................... 7
6. Acknowledgements ............................................ 7
APPENDIX - Reference Implementation ............................. 7
Security Considerations.......................................... 18
Author's Address................................................. 181. Abstract 🦋
Okay so this note describes the MD4 message digest algorithm 💜 It takes an input message of any length and spits out a 128-bit "fingerprint" or "message digest" of that input. The vibe is that it's conjectured to be computationally infeasible to make two messages with the same digest, or to make any message that hits a given target digest. Lowkey iconic, so it's ideal for digital signature stuff, where you "compress" a big file securely before signing it with the RSA public-key cryptosystem 🔐
MD4 is designed to be super fast on 32-bit machines 🚀 On a SUN Sparc station it runs at 1,450,000 bytes/second. On a DEC MicroVax II it runs at approximately 70,000 bytes/second. On a 20MHz 80286 it runs at approximately 32,000 bytes/second. And it doesn't need any big substitution tables, so it can be coded really compactly 🧁
The MD4 algorithm is being placed in the public domain for review and possible adoption as a standard 🌈
(Note: The document supersedes an earlier draft. The algorithm described here is a slight modification of the one described in the draft. ✨)
2. Terminology and Notation 🧠
In this note a "word" is a 32-bit quantity and a byte is an 8-bit quantity 🍓 A sequence of bits can be read naturally as a sequence of bytes, where each consecutive group of 8 bits is a byte, with the high-order (most significant) bit listed first. Same energy the other way: a sequence of bytes can be read as 32-bit words, where each group of 4 bytes is a word with the low-order (least significant) byte given first 💅
Let x_i denote "x sub i". If the subscript is an expression, we surround it in braces, as in x_{i+1}. We also use ^ for superscripts (exponentiation), so x^i means x to the i-th power 🤓
Let the symbol + denote addition of words (i.e., modulo-2^32 addition). Let X <<< s denote the 32-bit value you get by circularly shifting (rotating) X left by s bit positions 🔄 Let not(X) denote the bit-wise complement of X, and let X v Y denote the bit-wise OR of X and Y. Let X xor Y denote the bit-wise XOR of X and Y, and let XY denote the bit-wise AND of X and Y. Bit math is literally my whole personality rn 😭
3. MD4 Algorithm Description 🔥
We begin by supposing that we have a b-bit message as input, and that we wish to find its message digest. Here b is an arbitrary nonnegative integer. b may be zero, it need not be a multiple of 8, and it may be arbitrarily large 🫶 We imagine the bits of the message written down like this:
m_0 m_1 ... m_{b-1}The following five steps are performed to compute the message digest of the message 🎀
Step 1. Append padding bits 🧸
The message is "padded" (extended) so that its length (in bits) is congruent to 448, modulo 512. That means the message gets extended so that it's just 64 bits shy of being a multiple of 512 bits long ✨ Padding is always performed, even if the length of the message is already congruent to 448, modulo 512. In that case, 512 bits of padding get added. Main character energy 👑
Padding works like this: a single "1" bit is appended to the message, and then enough zero bits are appended so that the length in bits of the padded message becomes congruent to 448, modulo 512 💖
Step 2. Append length 📏
A 64-bit representation of b (the length of the message before the padding bits were added) is appended to the result of the previous step. In the unlikely event that b is greater than 2^64, then only the low-order 64 bits of b are used. (These bits are appended as two 32-bit words, with the low-order word first, following the previous conventions 🧚)
At this point the resulting message (after padding with bits and with b) has a length that's an exact multiple of 512 bits. Equivalently, its length is an exact multiple of 16 (32-bit) words. Let M[0 ... N-1] denote the words of the resulting message, where N is a multiple of 16 🦋
4. Extensions ✨
okay so if you need MORE than 128 bits of output, the recommended move is this little 256-bit upgrade 💅 (and no, there's no way to get more than 256 bits, sorry bestie 🙈)
so you run two copies of MD4 in parallel over the same input 👯♀️ The first copy is the standard one we already talked about. The second copy is the glow-up version, with a few changes:
The second copy starts with its own initial state:
word A: 00 11 22 33
word B: 44 55 66 77
word C: 88 99 aa bb
word D: cc dd ee ffand its magic constants in rounds 2 and 3 are swapped out. Instead of sqrt(2) and sqrt(3), it uses cuberoot(2) and cuberoot(3) 🔮
Octal Hex
Round 2 constant 012050505746 50a28be6
Round 3 constant 013423350444 5c4dd124last big thing 🫶 after every 16-word block is processed (including the last block), the A registers from the two copies get swapped 🔄
and then the final message digest is basically the first copy's result with the second copy's result tacked onto the end 🎀
5. Summary
okay the MD4 message digest algorithm is honestly so simple to implement 😭 and it gives you a "fingerprint" (aka a message digest) for a message of any length 🦋
it's conjectured that finding two messages with the same digest takes around 2^64 operations, and finding any message that matches a given digest takes around 2^128 operations 🤓 MD4 has been carefully poked at for weaknesses, BUT it's a relatively new algorithm, so more security analysis is totally justified, same as with any new proposal like this 💀 the security level should be sufficient for building very high security hybrid digital signature schemes based on MD4 and the RSA public-key cryptosystem ✨
6. Acknowledgements
big thank yous to Don Coppersmith, Burt Kaliski, Ralph Merkle, and Noam Nisan for all the helpful comments and suggestions 🫶💜
APPENDIX - Reference Implementation 🧚
okay this appendix is the reference implementation, and it comes with these files:
md4.h -- header file for using MD4 implementation
md4.c -- the source code for MD4 routines
md4driver.c -- a sample "user" routine
session -- sample results of running md4driverhere's the header file first 🎀
/*
** ********************************************************************
** md4.h -- Header file for implementation of **
** MD4 Message Digest Algorithm **
** Updated: 2/13/90 by Ronald L. Rivest **
** (C) 1990 RSA Data Security, Inc. **
** ********************************************************************
*/
/* MDstruct is the data structure for a message digest computation.
*/
typedef struct {
unsigned int buffer[4]; /* Holds 4-word result of MD computation */
unsigned char count[8]; /* Number of bits processed so far */
unsigned int done; /* Nonzero means MD computation finished */
} MDstruct, *MDptr;
/* MDbegin(MD)
** Input: MD -- an MDptr
** Initialize the MDstruct prepatory to doing a message digest
** computation.
*/
extern void MDbegin();
/* MDupdate(MD,X,count)
** Input: MD -- an MDptr
** X -- a pointer to an array of unsigned characters.
** count -- the number of bits of X to use (an unsigned int).
** Updates MD using the first "count" bits of X.
** The array pointed to by X is not modified.
** If count is not a multiple of 8, MDupdate uses high bits of
** last byte.
** This is the basic input routine for a user.
** The routine terminates the MD computation when count < 512, so
** every MD computation should end with one call to MDupdate with a
** count less than 512. Zero is OK for a count.
*/
extern void MDupdate();
/* MDprint(MD)
** Input: MD -- an MDptr
** Prints message digest buffer MD as 32 hexadecimal digits.
** Order is from low-order byte of buffer[0] to high-order byte
** of buffer[3].
** Each byte is printed with high-order hexadecimal digit first.
*/
extern void MDprint();
/*
** End of md4.h
****************************(cut)***********************************/and now the main implementation file, md4.c 💖
/*
** ********************************************************************
** md4.c -- Implementation of MD4 Message Digest Algorithm **
** Updated: 2/16/90 by Ronald L. Rivest **
** (C) 1990 RSA Data Security, Inc. **
** ********************************************************************
*/
/*
** To use MD4:
** -- Include md4.h in your program
** -- Declare an MDstruct MD to hold the state of the digest
** computation.
** -- Initialize MD using MDbegin(&MD)
** -- For each full block (64 bytes) X you wish to process, call
** MDupdate(&MD,X,512)
** (512 is the number of bits in a full block.)
** -- For the last block (less than 64 bytes) you wish to process,
** MDupdate(&MD,X,n)
** where n is the number of bits in the partial block. A partial
** block terminates the computation, so every MD computation
** should terminate by processing a partial block, even if it
** has n = 0.
** -- The message digest is available in MD.buffer[0] ...
** MD.buffer[3]. (Least-significant byte of each word
** should be output first.)
** -- You can print out the digest using MDprint(&MD)
*/
/* Implementation notes:
** This implementation assumes that ints are 32-bit quantities.
** If the machine stores the least-significant byte of an int in the
** least-addressed byte (e.g., VAX and 8086), then LOWBYTEFIRST
** should be set to TRUE. Otherwise (e.g., SUNS), LOWBYTEFIRST
** should be set to FALSE. Note that on machines with LOWBYTEFIRST
** FALSE the routine MDupdate modifies has a side-effect on its input
** array (the order of bytes in each word are reversed). If this is
** undesired a call to MDreverse(X) can reverse the bytes of X back
** into order after each call to MDupdate.
*/
#define TRUE 1
#define FALSE 0
#define LOWBYTEFIRST FALSE
/* Compile-time includes
*/
#include <stdio.h>
#include "md4.h"
/* Compile-time declarations of MD4 "magic constants".
*/
#define I0 0x67452301 /* Initial values for MD buffer */
#define I1 0xefcdab89
#define I2 0x98badcfe
#define I3 0x10325476
#define C2 013240474631 /* round 2 constant = sqrt(2) in octal */
#define C3 015666365641 /* round 3 constant = sqrt(3) in octal */
/* C2 and C3 are from Knuth, The Art of Programming, Volume 2
** (Seminumerical Algorithms), Second Edition (1981), Addison-Wesley.
** Table 2, page 660.
*/
#define fs1 3 /* round 1 shift amounts */
#define fs2 7
#define fs3 11
#define fs4 19
#define gs1 3 /* round 2 shift amounts */
#define gs2 5
#define gs3 9
#define gs4 13
#define hs1 3 /* round 3 shift amounts */
#define hs2 9
#define hs3 11
#define hs4 15
/* Compile-time macro declarations for MD4.
** Note: The "rot" operator uses the variable "tmp".
** It assumes tmp is declared as unsigned int, so that the >>
** operator will shift in zeros rather than extending the sign bit.
*/
#define f(X,Y,Z) ((X&Y) | ((~X)&Z))
#define g(X,Y,Z) ((X&Y) | (X&Z) | (Y&Z))
#define h(X,Y,Z) (X^Y^Z)
#define rot(X,S) (tmp=X,(tmp<<S) | (tmp>>(32-S)))
#define ff(A,B,C,D,i,s) A = rot((A + f(B,C,D) + X[i]),s)
#define gg(A,B,C,D,i,s) A = rot((A + g(B,C,D) + X[i] + C2),s)
#define hh(A,B,C,D,i,s) A = rot((A + h(B,C,D) + X[i] + C3),s)
/* MDprint(MDp)
** Print message digest buffer MDp as 32 hexadecimal digits.
** Order is from low-order byte of buffer[0] to high-order byte of
** buffer[3].
** Each byte is printed with high-order hexadecimal digit first.
** This is a user-callable routine.
*/
void
MDprint(MDp)
MDptr MDp;
{ int i,j;
for (i=0;i<4;i++)
for (j=0;j<32;j=j+8)
printf("%02x",(MDp->buffer[i]>>j) & 0xFF);
}
/* MDbegin(MDp)
** Initialize message digest buffer MDp.
** This is a user-callable routine.
*/
void
MDbegin(MDp)
MDptr MDp;
{ int i;
MDp->buffer[0] = I0;
MDp->buffer[1] = I1;
MDp->buffer[2] = I2;
MDp->buffer[3] = I3;
for (i=0;i<8;i++) MDp->count[i] = 0;
MDp->done = 0;
}
/* MDreverse(X)
** Reverse the byte-ordering of every int in X.
** Assumes X is an array of 16 ints.
** The macro revx reverses the byte-ordering of the next word of X.
*/
#define revx { t = (*X << 16) | (*X >> 16); \
*X++ = ((t & 0xFF00FF00) >> 8) | ((t & 0x00FF00FF) << 8); }
MDreverse(X)
unsigned int *X;
{ register unsigned int t;
revx; revx; revx; revx; revx; revx; revx; revx;
revx; revx; revx; revx; revx; revx; revx; revx;
}
/* MDblock(MDp,X)
** Update message digest buffer MDp->buffer using 16-word data block X.
** Assumes all 16 words of X are full of data.
** Does not update MDp->count.
** This routine is not user-callable.
*/
static void
MDblock(MDp,X)
MDptr MDp;
unsigned int *X;
{
register unsigned int tmp, A, B, C, D;
#if LOWBYTEFIRST == FALSE
MDreverse(X);
#endif
A = MDp->buffer[0];
B = MDp->buffer[1];
C = MDp->buffer[2];
D = MDp->buffer[3];
/* Update the message digest buffer */
ff(A , B , C , D , 0 , fs1); /* Round 1 */
ff(D , A , B , C , 1 , fs2);
ff(C , D , A , B , 2 , fs3);
ff(B , C , D , A , 3 , fs4);
ff(A , B , C , D , 4 , fs1);
ff(D , A , B , C , 5 , fs2);
ff(C , D , A , B , 6 , fs3);
ff(B , C , D , A , 7 , fs4);
ff(A , B , C , D , 8 , fs1);
ff(D , A , B , C , 9 , fs2);
ff(C , D , A , B , 10 , fs3);
ff(B , C , D , A , 11 , fs4);
ff(A , B , C , D , 12 , fs1);
ff(D , A , B , C , 13 , fs2);
ff(C , D , A , B , 14 , fs3);
ff(B , C , D , A , 15 , fs4);
gg(A , B , C , D , 0 , gs1); /* Round 2 */
gg(D , A , B , C , 4 , gs2);
gg(C , D , A , B , 8 , gs3);
gg(B , C , D , A , 12 , gs4);
gg(A , B , C , D , 1 , gs1);
gg(D , A , B , C , 5 , gs2);
gg(C , D , A , B , 9 , gs3);
gg(B , C , D , A , 13 , gs4);
gg(A , B , C , D , 2 , gs1);
gg(D , A , B , C , 6 , gs2);
gg(C , D , A , B , 10 , gs3);
gg(B , C , D , A , 14 , gs4);
gg(A , B , C , D , 3 , gs1);
gg(D , A , B , C , 7 , gs2);
gg(C , D , A , B , 11 , gs3);
gg(B , C , D , A , 15 , gs4);
hh(A , B , C , D , 0 , hs1); /* Round 3 */
hh(D , A , B , C , 8 , hs2);
hh(C , D , A , B , 4 , hs3);
hh(B , C , D , A , 12 , hs4);
hh(A , B , C , D , 2 , hs1);
hh(D , A , B , C , 10 , hs2);
hh(C , D , A , B , 6 , hs3);
hh(B , C , D , A , 14 , hs4);
hh(A , B , C , D , 1 , hs1);
hh(D , A , B , C , 9 , hs2);
hh(C , D , A , B , 5 , hs3);
hh(B , C , D , A , 13 , hs4);
hh(A , B , C , D , 3 , hs1);
hh(D , A , B , C , 11 , hs2);
hh(C , D , A , B , 7 , hs3);
hh(B , C , D , A , 15 , hs4);
MDp->buffer[0] += A;
MDp->buffer[1] += B;
MDp->buffer[2] += C;
MDp->buffer[3] += D;
}Okay bestie, this is where the code lives 💻✨ MDupdate is the heart of the whole thing, and it's giving main character energy 👑
/* MDupdate(MDp,X,count)
** Input: MDp -- an MDptr
** X -- a pointer to an array of unsigned characters.
** count -- the number of bits of X to use.
** (if not a multiple of 8, uses high bits of last byte.)
** Update MDp using the number of bits of X given by count.
** This is the basic input routine for an MD4 user.
** The routine completes the MD computation when count < 512, so
** every MD computation should end with one call to MDupdate with a
** count less than 512. A call with count 0 will be ignored if the
** MD has already been terminated (done != 0), so an extra call with
** count 0 can be given as a "courtesy close" to force termination
** if desired.
*/
void
MDupdate(MDp,X,count)
MDptr MDp;
unsigned char *X;
unsigned int count;
{ unsigned int i, tmp, bit, byte, mask;
unsigned char XX[64];
unsigned char *p;
/* return with no error if this is a courtesy close with count
** zero and MDp->done is true.
*/
if (count == 0 && MDp->done) return;
/* check to see if MD is already done and report error */
if (MDp->done)
{ printf("\nError: MDupdate MD already done."); return; }
/* Add count to MDp->count */
tmp = count;
p = MDp->count;
while (tmp)
{ tmp += *p;
*p++ = tmp;
tmp = tmp >> 8;
}
/* Process data */
if (count == 512)
{ /* Full block of data to handle */
MDblock(MDp,(unsigned int *)X);
}
else if (count > 512) /* Check for count too large */
{ printf("\nError: MDupdate called with illegal count value %d."
,count);
return;
}
else /* partial block -- must be last block so finish up */
{ /* Find out how many bytes and residual bits there are */
byte = count >> 3;
bit = count & 7;
/* Copy X into XX since we need to modify it */
for (i=0;i<=byte;i++) XX[i] = X[i];
for (i=byte+1;i<64;i++) XX[i] = 0;
/* Add padding '1' bit and low-order zeros in last byte */
mask = 1 << (7 - bit);
XX[byte] = (XX[byte] | mask) & ~( mask - 1);
/* If room for bit count, finish up with this block */
if (byte <= 55)
{ for (i=0;i<8;i++) XX[56+i] = MDp->count[i];
MDblock(MDp,(unsigned int *)XX);
}
else /* need to do two blocks to finish up */
{ MDblock(MDp,(unsigned int *)XX);
for (i=0;i<56;i++) XX[i] = 0;
for (i=0;i<8;i++) XX[56+i] = MDp->count[i];
MDblock(MDp,(unsigned int *)XX);
}
/* Set flag saying we're done with MD computation */
MDp->done = 1;
}
}
/*
** End of md4.c
****************************(cut)***********************************/okay so the driver file is next, and it's a whole vibe 🧚💜 it's the sample routines that test the MD4 algorithm, like the little sandbox where you poke at it before you trust it, iykyk 🎀
/*
** ********************************************************************
** md4driver.c -- sample routines to test **
** MD4 message digest algorithm. **
** Updated: 2/16/90 by Ronald L. Rivest **
** (C) 1990 RSA Data Security, Inc. **
** ********************************************************************
*/
#include <stdio.h>
#include "md4.h"
/* MDtimetrial()
** A time trial routine, to measure the speed of MD4.
** Measures speed for 1M blocks = 64M bytes.
*/
MDtimetrial()
{ unsigned int X[16];
MDstruct MD;
int i;
double t;
for (i=0;i<16;i++) X[i] = 0x01234567 + i;
printf
("MD4 time trial. Processing 1 million 64-character blocks...\n");
clock();
MDbegin(&MD);
for (i=0;i<1000000;i++) MDupdate(&MD,X,512);
MDupdate(&MD,X,0);
t = (double) clock(); /* in microseconds */
MDprint(&MD); printf(" is digest of 64M byte test input.\n");
printf("Seconds to process test input: %g\n,t/1e6);
printf("Characters processed per second: %ld.\n,(int)(64e12/t));
}
/* MDstring(s)
** Computes the message digest for string s.
** Prints out message digest, a space, the string (in quotes) and a
** carriage return.
*/
MDstring(s)
unsigned char *s;
{ unsigned int i, len = strlen(s);
MDstruct MD;
MDbegin(&MD);
for (i=0;i+64<=len;i=i+64) MDupdate(&MD,s+i,512);
MDupdate(&MD,s+i,(len-i)*8);
MDprint(&MD);
printf(" \"%s\"\n",s);
}
/* MDfile(filename)
** Computes the message digest for a specified file.
** Prints out message digest, a space, the file name, and a
** carriage return.
*/
MDfile(filename)
char *filename;
{ FILE *f = fopen(filename,"rb");
unsigned char X[64];
MDstruct MD;
int b;
if (f == NULL)
{ printf("%s can't be opened.\n",filename); return; }
MDbegin(&MD);
while ((b=fread(X,1,64,f))!=0) MDupdate(&MD,X,b*8);
MDupdate(&MD,X,0);
MDprint(&MD);
printf(" %s\n",filename);
fclose(f);
}
/* MDfilter()
** Writes the message digest of the data from stdin onto stdout,
** followed by a carriage return.
*/
MDfilter()
{ unsigned char X[64];
MDstruct MD;
int b;
MDbegin(&MD);
while ((b=fread(X,1,64,stdin))!=0) MDupdate(&MD,X,b*8);
MDupdate(&MD,X,0);
MDprint(&MD);
printf("\n");
}
/* MDtestsuite()
** Run a standard suite of test data.
*/
MDtestsuite()
{
printf("MD4 test suite results:\n");
MDstring("");
MDstring("a");
MDstring("abc");
MDstring("message digest");
MDstring("abcdefghijklmnopqrstuvwxyz");
MDstring
("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789");
MDfile("foo"); /* Contents of file foo are "abc" */
}
main(argc,argv)
int argc;
char *argv[];
{ int i;
/* For each command line argument in turn:
** filename -- prints message digest and name of file
** -sstring -- prints message digest and contents of string
** -t -- prints time trial statistics for 64M bytes
** -x -- execute a standard suite of test data
** (no args) -- writes messages digest of stdin onto stdout
*/
if (argc==1) MDfilter();
else
for (i=1;i<argc;i++)
if (argv[i][0]=='-' && argv[i][1]=='s') MDstring(argv[i]+2);
else if (strcmp(argv[i],"-t")==0) MDtimetrial();
else if (strcmp(argv[i],"-x")==0) MDtestsuite();
else MDfile(argv[i]);
}
/*
** end of md4driver.c
****************************(cut)***********************************/the sample session is literally the cutest part 🍓 it shows the whole compile-and-run flow on a SUN Sparcstation, so you can see the digests come out exactly the way they should ✨
--------------------------------------------------------------------
--- Sample session. Compiling and using MD4 on SUN Sparcstation ---
--------------------------------------------------------------------
>ls
total 66
-rw-rw-r-- 1 rivest 3 Feb 14 17:40 abcfile
-rwxrwxr-x 1 rivest 24576 Feb 17 12:28 md4
-rw-rw-r-- 1 rivest 9347 Feb 17 00:37 md4.c
-rw-rw-r-- 1 rivest 25150 Feb 17 12:25 md4.doc
-rw-rw-r-- 1 rivest 1844 Feb 16 21:21 md4.h
-rw-rw-r-- 1 rivest 3497 Feb 17 12:27 md4driver.c
>
>cc -o md4 -O4 md4.c md4driver.c
md4.c:
md4driver.c:
Linking:
>
>md4 -x
MD4 test suite results:
31d6cfe0d16ae931b73c59d7e0c089c0 ""
bde52cb31de33e46245e05fbdbd6fb24 "a"
a448017aaf21d8525fc10ae87aa6729d "abc"
d9130a8164549fe818874806e1c7014b "message digest"
d79e1c308aa5bbcdeea8ed63df412da9 "abcdefghijklmnopqrstuvwxyz"
043f8582f241db351ce627e153e7f0e4
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789"
a448017aaf21d8525fc10ae87aa6729d abcfile
>
>md4 -sabc -shi
a448017aaf21d8525fc10ae87aa6729d "abc"
cfaee2512bd25eb033236f0cd054e308 "hi"
>
>md4 *
a448017aaf21d8525fc10ae87aa6729d abcfile
d316f994da0e951cf9502928a1f73300 md4
379adb39eada0dfdbbdfdcd0d9def8c4 md4.c
9a3f73327c65954198b1f45a3aa12665 md4.doc
37fe165ac177b461ff78b86d10e4ff33 md4.h
7dcba2e2dc4d8f1408d08beb17dabb2a md4.o
08790161bfddc6f5788b4353875cb1c3 md4driver.c
1f84a7f690b0545d2d0480d5d3c26eea md4driver.o
>
>cat abcfile | md4
a448017aaf21d8525fc10ae87aa6729d
>
>md4 -t
MD4 time trial. Processing 1 million 64-character blocks...
6325bf77e5891c7c0d8104b64cc6e9ef is digest of 64M byte test input.
Seconds to process test input: 44.0982
Characters processed per second: 1451305.
>
>
------------------------ end of sample session --------------------Note: a version of this doc with the C source code is up for FTP from THEORY.LSC.MIT.EDU in the file "md4.doc" 📂 go grab it 🫶
Security Considerations 🔐
The level of security discussed in this memo by MD4 is considered to be sufficient for implementing very high security hybrid digital signature schemes based on MD4 and the RSA public-key cryptosystem. 🔥 Bestie, this is the big one: MD4 is the hash here, and it's being called sufficient for very high security hybrid digital signature schemes built on MD4 and RSA public-key cryptography 💅
Author's Address 🎀
Ronald L. Rivest
Massachusetts Institute of Technology
Laboratory for Computer Science
NE43-324
545 Technology Square
Cambridge, MA 02139-1986
Phone: (617) 253-5880
EMail: rivest@theory.lcs.mit.eduAnd that's the whole RFC, periodt 🌈💖
📦 where this page comes from
- ietf: rfc1186 1990-10
- 💖 girlified by claude-haiku-5-5 on : a language model's rewrite of the original, under its terms