chain code #2

Here's another 'chain' code.

The algorithm for solving it follows the encoded message.

QQONGBUASLPNMGC OUKG YNNTEKWWGY YC YMYWJ Y KVJFSL

YYMVHRAY TQZC QOOE IWW WQGSPQGF UW SD KOXIP DKPPZX IJ

GXOZAWMW TADU AXSF UY EHSH, ZAH PVMX CWMPBLFWKJ

IWUMKCPZ XI UIM, NBXKBCNMGJ HDU, ZOOT GXOZAWMA

PWGAOQGF ZAN SIDPYM IX EKTCH WFF ZOOO PCMWXZ EKTCH IWG

MZNPKFAWBGX ID YYMVHRAMT. KBUDCSGY YL SYIP-QKHYIGZ

AZHK, ZAF OEDPBQJWD HEJV-PWZTWVKGC LREOCUGV WZTHCNOZM

ZOOU IU S IHHT TQZO I WQVCSALWB EHSC, QHULDCZAWK MWBGJ

ZNWJM GJCC YD OKOWZM. QGC AXSA WFF EHSC IWJ GSDGO TQZT

ZAV VSPIYBU ID QHIQE SOSWMM. ZAW WZMU IZ ZAA WCUB,

OYPQVT KSN GIWE SHHWR OPTJ, CEHXQ YNMCYCIJ DKPPZX IZ

MQZGH WFP SSCTLKBGM ZOOE CJCXIP UO OUKA SJKP PIVXQCWKM

GXOZAWMX. GB ZAA GPHHX IS QGJ CESPT KSWEAVCIH IWQ

QOJQWXYX II QOOL SJXM APRH PCMWXZ EKTP GXOZAWMX. YZAWT

YYMVHRAJ WHZHYYV TQZC QOOE CJCXIP UW SM GXOZAWRAPRC

DKPPZC OUKA SJKE OIXIPZAGY YV WDPKBY BXIMK, OGR

MYZMYOR LN TDSXOCQX LM ZMNJ ACDBVLKP, QQONGBUASLPNMGJ

HHUM. CKYAGY YB ZAW AZHM APRX Y SSADQWJG MDTSKOCBGY

PAJABOFYYOW ZAZ LREOCUGW IWV VSPIYBGX II QAWWC ZAG

QHIW WFP GXOZAWMH CJCXIP UO OUKA SJKP.

The last one was encrypted like this:

To encrypt 'like a[...m]' (m being the last letter of the plain text):

encrypt(l) = letter((num(m) + num(l)) mod 26) = letter((13 + 12) mod 26) = letter(25) = Y

encrypt(i) = letter((num(l) + num(i)) mod 26) = letter((12 + 9) mod 26) = letter(21) = U

encrypt(k) = letter((num(i) + num(k)) mod 26) = letter((9 + 11) mod 26) = letter(20) = T

encrypt(e) = letter((num(k) + num(e)) mod 26) = letter(11 + 5 mod) = letter (16) = P

encrypt(a) = letter((num(e) + num(a)) mod 26) = letter (6) = F

This one is chained similarly (not exactly the same), but the 2 numbers have constant multipliers and a 3rd constant is added similar to this:

encrypt(x) = letter((a * num(y) + b * num(z) + c)) mod

a = 1, b = 10, c = 24 (or something like that):

paleontologists have discovered in china a fossil...

This is a form of plaintext autokey, if you're trying to find a classification for your invention.